CN113283033B - Optimized design method and device for elastic strip and storage medium - Google Patents
Optimized design method and device for elastic strip and storage medium Download PDFInfo
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Abstract
The invention discloses an optimal design method and device for a spring strip and a storage medium, and belongs to the technical field of rail transit. Obtaining basic parameters of the elastic strip according to the space geometric relation of the elastic strip, and endowing the basic parameters with current parameter values and current moving step length according to a preset mechanism; calculating to obtain a current optimization subarea and a current numerical test result by using the current parameter value and the current moving step length; constructing a current approximate constraint equation meeting the elastic band constraint condition according to a current numerical test result by using a regression analysis method, and solving to obtain a current approximate optimal solution; if the range of the current optimization subarea is not larger than the preset range, determining the current approximate optimization solution as an approximate solution, and if the range of the current optimization subarea is larger than the preset range, calculating the next approximate optimization solution according to a preset mechanism. The method has the advantages of strong applicability, higher efficiency of the calculation process and more accurate optimization result.
Description
Technical Field
The invention relates to the technical field of rail transit, in particular to an optimal design method and device for elastic strips and a storage medium.
Background
The existing bullet strip design method firstly puts forward the design parameters of bullet strip buckling pressure, bullet stroke and residual deformation according to the requirements of a track structure, and then establishes the basic structure and the geometric dimension of the bullet strip. And then, calculating the stress state of each position of the elastic strip during working by adopting an elastoplastic finite element method, calculating corresponding stress, and determining the position of the dangerous point. After the dangerous point is determined, strength and fatigue performance are checked. And finally, changing the structure of the elastic strip according to the checking result of the strength and the fatigue performance, and checking the buckling force, the elastic stroke, the strength, the residual deformation and the fatigue strength again until the performance requirement is met.
In the prior art, only stress distribution and displacement change of the elastic strip are considered, the inherent vibration frequency and modal characteristics of the elastic strip are not considered, performance hidden danger exists, and the prior art mainly comprises the steps of carrying out finite element analysis firstly, then repeatedly modifying parameters to carry out checking, and the method has the advantages of large workload and long time consumption. The optimization range of the prior art is smaller, and the optimization requirements of different track structures cannot be met.
Disclosure of Invention
Aiming at the problems existing in the prior art, the invention mainly provides an optimal design method and device for a spring strip and a storage medium.
In order to achieve the above purpose, the invention adopts a technical scheme that: the utility model provides an optimization design method of a spring strip, which comprises the following steps: obtaining basic parameters of the elastic strip according to the space geometric relation of the elastic strip, and endowing the basic parameters with current parameter values and current moving step length according to a preset mechanism; calculating a current optimization subarea by using the current parameter value of each basic parameter and the current moving step length of each basic parameter, and a group of current numerical test results comprising a buckling force value, a maximum stress value, an inherent frequency value and an energy value stored in unit mass; constructing a current approximate constraint equation meeting the geometric form, the safety buckling force and the material yield strength of the elastic strip, the excitation frequency range of the track response and the maximum energy stored in unit mass according to the current numerical test result by using a regression analysis method, and solving the current approximate constraint equation in a current optimization subarea to obtain a current approximate optimization solution of basic parameters; and if the range of the current optimization subarea is not greater than the preset range, determining the current approximate optimization solution as an approximate solution, and if the range of the current optimization subarea is greater than the preset range, obtaining a next parameter value and a next moving step length of the basic parameter according to a preset mechanism, and calculating the next approximate optimization solution according to the next parameter value and the next moving step length of the basic parameter; the preset mechanism is to assign an initial parameter value and an initial movement step length to the basic parameter according to an empirical value, take a current approximate optimal solution as a next parameter value of the basic parameter, and calculate the next movement step length of the basic parameter according to the current approximate optimal solution and a last approximate optimal solution.
The invention adopts another technical scheme that: an apparatus for optimally designing a spring strip is provided, comprising: the basic parameter acquisition module is used for acquiring basic parameters of the elastic strip according to the space geometric relation of the elastic strip, and endowing the basic parameters with current parameter values and current moving step sizes according to a preset mechanism; the intermediate data acquisition module is used for calculating a current optimization subarea by using the current parameter value of each basic parameter and the current moving step length of each basic parameter, and a group of current numerical test results comprising a buckling force value, a maximum stress value, an inherent frequency value and a unit mass stored energy value; the current approximate optimization solution acquisition module is used for constructing a current approximate constraint equation meeting the maximum of the geometric form, the safety buckling pressure and the material yield strength of the elastic strip, the excitation frequency range of the track response and the energy stored in unit mass according to the current numerical test result by using a regression analysis method, and solving the current approximate constraint equation in the current optimization subarea to obtain a current approximate optimization solution of the basic parameters; the approximate solution judging module is used for determining the current approximate optimal solution as an approximate solution if the range of the current optimal subarea is not larger than a preset range, obtaining the next parameter value and the next moving step length of the basic parameter according to a preset mechanism if the range of the current optimal subarea is larger than the preset range, and calculating the next approximate optimal solution according to the next parameter value and the next moving step length of the basic parameter; the preset mechanism is to assign an initial parameter value and an initial movement step length to the basic parameter according to an empirical value, take a current approximate optimal solution as a next parameter value of the basic parameter, and calculate the next movement step length of the basic parameter according to the current approximate optimal solution and a last approximate optimal solution.
The invention adopts another technical scheme that: a computer readable storage medium is provided that stores computer instructions that are operable to perform a method of optimizing design of a spring in scenario one.
The technical scheme of the invention has the following beneficial effects: the invention designs an optimal design method, device and storage medium of a spring strip. The method can adjust the approximate constraint equation according to different design requirements, has strong applicability and can meet the optimization requirements of different track structures. The natural frequency and modal characteristics of the elastic strip are considered, so that the designed elastic strip performance is more reliable, and the result calculation is directly performed by utilizing finite element software, so that the calculation process is higher in efficiency, and the optimization result is more accurate.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it will be obvious that the drawings in the following description are some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort to a person skilled in the art.
FIG. 1 is a schematic diagram of an embodiment of a method of optimizing a spring strip according to the present invention;
FIG. 2 is a schematic view of another embodiment of an apparatus for optimizing the design of a spring strip according to the present invention;
FIG. 3 is a schematic diagram of a front view of a W-shaped spring strip in one embodiment of a method for optimizing the design of the spring strip according to the present invention;
FIG. 4 is a schematic diagram of an expanded view of a W-shaped spring strip in a specific embodiment of a method for optimizing a spring strip according to the present invention;
FIG. 5 is a schematic diagram of a front view of a finite element model of a W-shaped spring strip in one embodiment of a method for optimizing the design of the spring strip according to the present invention;
FIG. 6 is a schematic diagram of an expanded view of a W-shaped spring strip finite element model of a W-shaped spring strip in an embodiment of a method for optimizing a spring strip according to the present invention.
Specific embodiments of the present invention have been shown by way of the above drawings and will be described in more detail below. The drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but rather to illustrate the inventive concepts to those skilled in the art by reference to the specific embodiments.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making clear and defining the scope of the present invention.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.
The fastener system is an important component of a railway structure, the elastic strip generates buckling force through bending and twisting deformation, and the steel rail is fixed on a sleeper of a ballast bed so as to ensure long-term effective and reliable connection with the steel rail, prevent the steel rail from moving vertically and horizontally relative to the sleeper and ensure the track gauge to be normal, thereby ensuring the running safety of a railway vehicle. The failure problem of the elastic strip of the fastener at present has become the focus of attention for maintenance and repair of railway tracks, and the reliability of the elastic strip of the fastener is directly related to driving safety. Therefore, optimizing the spring clip during the design phase is important to reduce the failure damage of the spring clip. The existing spring strip design method mainly considers the strength problems of stress, spring stroke and the like of the spring strip, does not consider the vibration frequency and modal characteristics of the spring strip, and has large calculated amount and low efficiency.
The optimal design method of the elastic strip provided by the invention has the following applicable scenes: the field of rail transit is applied to industries such as railway and urban rail transit.
Fig. 1 shows a specific embodiment of an optimization design method of the spring strip of the present invention.
S101, obtaining basic parameters of the elastic strip according to the space geometric relation of the elastic strip, and endowing the basic parameters with current parameter values and current moving step length according to a preset mechanism;
s102, calculating a current optimization subarea by using the current parameter value of each basic parameter and the current moving step length of each basic parameter, and a group of current numerical test results comprising a buckling force value, a maximum stress value, an inherent frequency value and an energy value stored in unit mass;
s103, constructing a current approximate constraint equation meeting the geometric form, the safety buckling pressure and the material yield strength of the elastic strip, the excitation frequency range of the track response and the maximum energy stored in unit mass according to the current numerical test result by using a regression analysis method, and solving the current approximate constraint equation in a current optimization subarea to obtain a current approximate optimization solution of basic parameters; the method comprises the steps of,
s104, if the range of the current optimization subarea is not larger than the preset range, determining the current approximate optimization solution as an approximate solution, if the range of the current optimization subarea is larger than the preset range, obtaining a next parameter value and a next moving step length of the basic parameter according to a preset mechanism, and calculating the next approximate optimization solution according to the next parameter value and the next moving step length of the basic parameter;
the preset mechanism is to assign an initial parameter value and an initial movement step length to the basic parameter according to an empirical value, take a current approximate optimal solution as a next parameter value of the basic parameter, and calculate the next movement step length of the basic parameter according to the current approximate optimal solution and a last approximate optimal solution.
According to the method, the natural frequency and the modal characteristics of the elastic strip are considered in the design process of the elastic strip, so that the designed elastic strip is excellent in performance, constraint conditions can be changed according to different requirements of the track on which the elastic strip is mounted, and the applicability is high. The method utilizes finite elements to directly perform result calculation, so that the optimization result obtained by calculation is accurate, and the process efficiency of calculation is higher by performing iterative calculation.
In the specific embodiment shown in fig. 1, the method for optimizing the design of the elastic strip includes step S101, obtaining a basic parameter of the elastic strip according to a spatial geometrical relationship of the elastic strip, and assigning a current parameter value and a current moving step length to the basic parameter according to a predetermined mechanism.
In one embodiment of the invention, the basic parameters of the spring are obtained from the spatial geometrical relationship of the spring. Meanwhile, according to the space geometrical relationship of the elastic strip, a parameterization equation of the elastic strip about the central axis is deduced. And establishing a parameterized finite element model of the elastic strip in a standard installation state by using a parameterized equation of the elastic strip about the central axis. Optimization of spring parameters is performed in the finite element model.
Preferably, in order to reduce the calculation amount and ensure the calculation accuracy, the parameterized finite element model of the elastic strip in the standard installation state adopts a nonlinear beam unit model. Meanwhile, the classical Hertz contact theory is adopted to determine the contact rigidity between the gauge baffle and the screw spike as well as between the screw spike and the spring strip.
According to the embodiment, the basic parameters of the elastic strip are obtained through the space geometric relationship of the elastic strip, the parameterized model of the elastic strip is established, and in the design process, the parameter results obtained by the elastic strip are more accurate and have stronger universality.
In a specific embodiment of the present invention, step S101 further includes deriving a spatial position and a spatial geometry of a central axis of the spring strip according to a structural view of the spring strip; and obtaining the basic parameters of the elastic strip according to the space position and the space geometric dimension of the central axis by using a parameterization equation.
In one embodiment of the present invention, the spatial position and spatial geometry of the central axis of the W-shaped spring strip will be derived from the spatial geometry of the W-shaped spring strip as shown in fig. 3 and 4. The basic space geometrical parameters of the W-shaped elastic strip shown in table 1 are deduced by using parameterization equations according to the space position and the space geometrical dimensions of the central axis of the W-shaped elastic strip.
TABLE 1
The initial parameter values are empirically assigned to the basic parameters of the W-shaped spring strips in table 1 to obtain the initial parameter values of the W-shaped spring strips. And then giving corresponding movement step length of each basic parameter according to experience to obtain the initial movement step length of the W-shaped elastic strip. And obtaining the contact rigidity among all the parts forming the W-shaped elastic strip by using a classical Hertz contact theory.
According to the specific example, the space geometric parameters of the W-shaped elastic strip are built through a finite element model, quantitative information of the W-shaped elastic strip is changed, and convenience is brought to performance optimization of the W-shaped elastic strip in the later period.
In one embodiment of the present invention, the optimization design of the W-shaped spring strip is performed using the material properties as in table 2.
| Material name | Modulus of elasticity/Mpa | Poisson's ratio | Yield strength/Mpa | Tensile Strength/Mpa | density/Kg.m -3 |
| 60Si 2 Mn | 206000 | 0.3 | 1590 | 1630 | 7850 |
TABLE 2
And (3) optimally designing the W-shaped spring strip by adopting a beam188 nonlinear beam unit model in finite element software ANSYS. Wherein, the grid density of the W-shaped elastic strip is set to be 1mm, and the section diameter d is set to be 14mm. The finite element model of the W-shaped elastic strip obtained after grid division is shown in fig. 5 and 6.
The standard installation state of the W-shaped elastic strip is that the jaw at the front end of the middle part of the elastic strip is just contacted with the gauge baffle, the arcs at the two tail parts are simultaneously supported in the groove of the gauge baffle, and the two toes at the front end are buckled and pressed at the front part of the gauge baffle. And analyzing by utilizing a finite element model of the W-shaped elastic strip to obtain displacement constraint in the y direction and the z direction required to be applied to the tail part of the W-shaped elastic strip, applying displacement constraint in the y direction to two toes at the front end of the elastic strip, and applying constraint in the z direction to the contact position of the middle limb of the elastic strip and the bolt.
According to the embodiment, the space geometric parameters of the W-shaped elastic strip are subjected to finite element model building, so that the research and development design efficiency and quality of the W-shaped elastic strip can be greatly improved, the research and development design period of the W-shaped elastic strip can be effectively shortened, and the calculation cost and the development cost are reduced.
In the specific embodiment shown in fig. 1, the method for optimizing the spring strip further includes step S102, calculating a current optimizing sub-area by using the current parameter value of each basic parameter and the current moving step length of each basic parameter, and a set of current numerical test results including a buckling force value, a maximum stress value, an inherent frequency value and a stored energy value of unit mass.
In a specific embodiment of the present invention, in the process of optimizing the spring strip, in order to ensure the accuracy of the optimizing result, an L plus 1 number of times value test is required, where L is the number of basic parameters of the spring strip that need to be optimized. In the optimization process of the elastic strip, L is added 1 time to substitute the parameter value into the finite element model, and the buckling pressure value, the maximum stress value, the inherent frequency value and the energy value stored in unit mass of the elastic strip are obtained through calculation.
According to the embodiment, the buckling pressure value, the maximum stress value, the inherent frequency value and the energy value stored in unit mass corresponding to the spring strip parameter value are obtained through numerical test calculation, and a foundation is laid for verifying whether the performance corresponding to the spring strip parameter value meets the design requirement.
In the specific embodiment shown in fig. 1, the method for optimizing the design of the elastic strip further includes step S103, constructing a current approximate constraint equation meeting the maximum of the geometric form, the safety buckling pressure, the material yield strength, the excitation frequency range of the track response and the energy stored in unit mass of the elastic strip according to the current numerical test result by using a regression analysis method, and solving the current approximate constraint equation in the current optimized sub-area to obtain a current approximate optimized solution of the basic parameters.
In one embodiment of the invention, the regression analysis is used to process the numerical test results and construct the current approximate constraint equation based on the geometry of the spring strip, the safety buckling pressure and material yield strength, the excitation frequency range of the rail response, and the condition of maximum stored energy per unit mass. And solving a current approximate constraint equation to a current approximate optimal solution of the basic parameters, wherein the current approximate optimal solution is in a corresponding current optimal sub-area.
The current approximate constraint equation solving method uses regression quantityAnd calculating the tuning parameter a to obtain a current approximate constraint equation. Specifically, use formula->a＝[a 1 ，a 2 ,…，a L ] T Calculating to obtain a current approximate constraint equation, wherein +.>Is the current approximation constraint equation. The tuning parameter a is obtained by fitting calculation by using a least square method, namely, the formula +.>Calculated, where w p Representing the last timeApproximation constraint equation at x P A weighting coefficient at the location; />Then x is represented as P Regression magnitude at F is the current approximation constraint equation.
According to the embodiment, the foundation is laid for optimizing calculation by using a computer by constructing the property of the constraint basic parameters of the current approximate constraint equation, so that the calculated amount is reduced, and the applicability of the optimizing design process is improved.
In one embodiment of the present invention, the spring strip obtained after the optimization design should satisfy: basic geometric relations of the elastic strips are met among basic parameters of the elastic strips so as to ensure the geometric form of the elastic strips; in a standard installation state, the optimized elastic strip can meet a certain buckling pressure without stress damage; the optimized spring strip should meet the requirement that the natural vibration frequency of the spring strip avoids the excitation frequency range of the track response in the standard installation state. Therefore, in the optimization process, the approximate optimal solution needs to be obtained according to the geometry of the spring strip, the safety buckling pressure and the material yield strength, and the excitation frequency range constraint of the track response and the maximum constraint of the stored energy per unit mass. Meanwhile, the method can also carry out further condition constraint according to the problems or needs of users in the field.
According to the embodiment, the range of the current optimization subarea is further narrowed by stipulating constraint conditions, so that the calculated amount in the spring strip design process is reduced, and the design efficiency is improved. By considering the natural frequency of the elastic strip and the excitation frequency range of the track response, the performance of the designed elastic strip is more excellent.
In a specific embodiment of the present invention, step S103 further includes establishing a geometric constraint equation by using a regression analysis method according to the value in the current optimization sub-area and the geometric form of the elastic strip, so as to ensure that each part of the elastic strip does not collide.
In a specific example of the invention, taking a W-shaped elastic strip as an example, in order to ensure the geometric form of the W-shaped elastic strip, the W-shaped elastic strip is designed to meet the following requirementsAnd F 2 (x)＝H 2 -H > 0 geometric constraint, wherein F 1 (x) And F 2 (x) R is a first geometry constraint and a second geometry constraint, respectively 2 、b 1 、b 2 、H 2 And H has the meanings indicated in Table 1, and (2)>D in (a) represents the spring diameter.
According to the embodiment, the current approximate optimal solution is obtained through constraint of the geometric form constraint condition, and under the condition that the geometric form of the W-shaped elastic strip is guaranteed, the calculated amount in the design process is further reduced, and the design efficiency is improved.
In a specific embodiment of the present invention, step S103 further includes establishing a stress condition constraint equation by using a regression analysis method according to the value in the current optimized sub-area, the safe buckling pressure of the elastic strip, and the material yield strength, so as to ensure that the elastic strip meets a certain buckling pressure in a standard installation state and no stress damage occurs.
In a specific example of the invention, taking a W-shaped elastic strip as an example, in order to ensure that the designed W-shaped elastic strip meets a certain buckling pressure and does not generate stress damage in a standard installation state, the designed W-shaped elastic strip needs to meet F 3 (x)＝P＞P 0 And F 4 (x)＝σ max ＞σ s 。F 3 (x) And F 4 (x) The third stress condition constraint equation and the fourth stress condition constraint equation are respectively adopted, wherein P is buckling force of the W-shaped elastic strip in a standard installation state, and P is 0 For the specified buckling force sigma required to be satisfied by the W-shaped elastic strip in the standard installation state max Is the maximum stress sigma which can be born by the W-shaped elastic strip in the standard installation state s The material yield strength of the W-shaped elastic strip. Taking Table 2 as an example, the stress constraint equation of the W-shaped spring strip is
According to the embodiment, the current approximate optimal solution is obtained through the constraint of the stress condition constraint equation, and under the condition that the stress and the buckling pressure of the W-shaped elastic strip meet the design requirement, the calculated amount in the design process is further reduced, the design efficiency is improved, and meanwhile, the W-shaped elastic strip performance is guaranteed to be better.
In a specific embodiment of the present invention, step S103 further includes establishing a natural frequency condition constraint equation by using a regression analysis method according to the value in the current optimized sub-area and the excitation frequency range of the track response, so as to ensure that the natural vibration frequency of the elastic strip in the standard installation state avoids the excitation frequency range of the track response.
In a specific example of the invention, taking a W-shaped elastic strip as an example, in order to ensure that the W-shaped elastic strip obtained by design meets the excitation frequency range of the self-vibration frequency avoidance track response of the W-shaped elastic strip in the standard installation state, the W-shaped elastic strip obtained by design needs to meet F 5 (x)＝f 1 ＜f min And F 6 (x)＝f 2 ＞f max 。F 5 (x) And F 6 (x) A fifth natural frequency condition constraint equation and a sixth natural frequency condition constraint equation, respectively, wherein f 1 And f 2 The first-order natural vibration frequency and the second-order natural vibration frequency of the W-shaped elastic strip in the standard installation state are f min And f max The lower and upper limits of the responsive excitation frequency range for the track to which the W-shaped spring is secured.
For example, the high frequency excitation of the steel rail is between 530 and 700Hz when the running speed of the motor train unit reaches 300 km/h. In order to avoid damage caused by resonance between the elastic strip and the excitation frequency, the self-vibration frequency of the elastic strip in the standard installation state should avoid the responsive excitation frequency range as much as possible. Thus, the constraint equation can be set as:
according to the embodiment, the current approximate optimal solution is obtained through establishing a natural frequency condition constraint equation constraint, so that the calculated amount in the design process is further reduced and the design efficiency is improved under the condition that the stress and the buckling pressure of the elastic strip meet the design requirements. Meanwhile, the relation between the natural frequency of the elastic strip and the excitation frequency range of the track response is considered in the design process, so that the elastic strip obtained by design is better in performance, service life and effect.
In the specific embodiment shown in fig. 1, the method for optimizing the bullet strip further includes step S104, if the range of the current optimizing sub-region is not greater than the predetermined range, determining the current approximate optimizing solution as an approximate solution, if the range of the current optimizing sub-region is greater than the predetermined range, obtaining a next parameter value and a next moving step of the basic parameter according to the predetermined mechanism, and calculating the next approximate optimizing solution according to the next parameter value and the next moving step of the basic parameter.
In one embodiment of the invention, the method is performed by the formulaCalculating to obtain a moving step length of the current parameter value under the corresponding basic parameter coordinate axis, wherein A, B is respectively a lower limit and an upper limit of each basic parameter, < ->Is the current approximate optimal solution, < >>Is the next approximate optimization solution; h k Is the last moving step of each basic parameter under the corresponding coordinate axis. Preferably, the initial movement step length takes a value of H 1 ＝0.25。
Based on the current parameter value of each basic parameter and the current movement step length of each basic parameter, using the formulaCalculating to obtain a current optimized subarea, wherein A is i k Is the lower limit value in the current optimization subarea, B i k Is the upper limit in the current optimization sub-area. Preferably, if->λ=1.6, μ=0.5; if->λ=0.5 and μ=1.6.
In a specific example of the present invention, according to design requirements, a current moving step length of a current parameter value of each basic parameter of the W-shaped spring strip under a corresponding coordinate axis is obtained. And calculating each current parameter value according to the current moving step length under the corresponding coordinate axis to obtain a current optimization subarea corresponding to each current parameter value. The current optimization subarea comprises a plurality of parameter values, and the current optimization subarea is determined according to the maximum value and the minimum value in the plurality of parameter values. The current optimization sub-region is a search range for the approximate optimization solution.
According to the embodiment, the current optimization subarea is obtained through calculation, the optimization range of the parameter value is determined, the optimization efficiency is improved, the reliability of the optimization result is ensured, and the calculated amount in the design process is further reduced.
In one embodiment of the present invention, the current approximate optimization solution is determined to be an approximate solution if the scope of the current optimization sub-region is not greater than the scope specified by the designer. If the range of the current optimization subarea is larger than the range specified by the designer, taking the current approximate optimization solution as the next parameter value of the basic parameter and calculating according to the current approximate optimization solution and the last approximate optimization solution to obtain the next moving step length of the basic parameter, and recalculating the next approximate optimization solution according to the next parameter value of the basic parameter and the next moving step length and carrying out judgment again. Specifically, in the process of optimizing the solution, the moving pace is adjusted by changing the moving pace of the current optimizing subarea, namely, a formula is utilizedChanging the timeA pre-optimization sub-region, where τ is the reduction coefficient.
In one embodiment of the present invention, in the kth optimization solution process, the approximate quality r needs to be evaluated first k Precision epsilon of current approximate optimization solution k ，
Wherein F is j Is the current approximate optimal solution and,is the last approximate optimization solution, F max The maximum value in the approximate optimal solution obtained in the k times of optimal solution process is eta, eta is a small positive number, A is the lower limit value of the current optimal subarea, and B is the upper limit value of the current optimal subarea.
After the current approximate optimal solution is calculated, if r k ≧ε k If the calculated current approximate optimal solution is not accurate enough, the optimal sub-area is reduced according to the reduction coefficient tau, the current approximate optimal solution is used as the last approximate optimal solution, the current optimal sub-area is used as the last optimal sub-area, and the approximate optimal solution is re-calculated, wherein tau=tau at the moment bad ，τ bad ＞1。
After the current approximate optimal solution is calculated, if r k ≤ε k However, if the range of the current optimization sub-region is not smaller than the range specified by the designer, the optimization sub-region is scaled down according to the scaling factor τ, and the approximate optimization solution is re-obtained, where τ=τ good ，τ good ＞1。
After the current approximate optimal solution is calculated, if r k ≤ε k And the range of the current optimization subarea is smaller than the range specified by the designer, the current optimization subarea is close toThe quasi-optimal solution is determined as an approximate solution.
According to the embodiment, the approximate solution is judged by judging the range of the optimization subarea and the preset range, so that the optimization result is more accurate, the design requirement is met, and the elastic strip performance obtained by design is more excellent.
In a specific embodiment of the present invention, step S104 further includes determining whether the approximate solution is an optimal solution according to the position of the approximate solution in the current optimization sub-region; if the approximate solution is not equal to the value at the end point of the current optimization subarea, determining the approximate solution as an optimal solution; if the approximate solution is equal to the value at the endpoint of the current optimized sub-region, obtaining the next parameter value and the next moving step of the basic parameter according to a preset mechanism, and calculating the next approximate optimized solution according to the next parameter value and the next moving step of the basic parameter
In a specific embodiment of the present invention, during the optimization process, when the range of the current optimization sub-region is continuously adjusted, an accurate optimization sub-region cannot be obtained after multiple calculations are performed, and this phenomenon is called a concussion phenomenon. In order to avoid oscillation phenomenon in the optimization process, the formula is utilized by utilizing the calculated approximate solution, the last approximate solution and the last approximate solutionFor oscillation factor theta k Evaluate and Θ k ∈[-1,1]。
If Θ is k Is positive, i.e. theta k ∈[0,1]The optimization process is good, no vibration phenomenon occurs, and the obtained approximate solution is the optimal solution.
If Θ is k Is negative, i.e. theta k ∈[-1,0]And describing that the oscillation phenomenon occurs in the optimization process.
In order to avoid oscillation after calculation of the bullet optimization approximation solution, the search sub-area is reduced by a reduction factor τ, where τ=τ osc ，τ osc ＞1。
If r k ≤ε k And the approximate solution is in the current optimization subAt the end points of the region, and the current approximate solution and the last approximate solution move in the same step direction when adjusting the optimized sub-region, i.e. 1- ρ +|Θ i When i is less than or equal to 1, i=k, k-1, …, k-l+1, the search sub-region is expanded by the reduction coefficient τ, at which time τ=τ enlrg ，0＜τ enlrg < 1 and 0 < ρ < 1.
According to the embodiment, whether the approximate solution is at the end point of the current optimization subarea is judged, the optimization subarea corresponding to the approximate solution is adjusted, the oscillation phenomenon is avoided, the optimization efficiency is improved, and the calculated amount is reduced.
In one embodiment of the invention, the energy stored per unit mass of the spring strip in the standard installation state, i.e. the spring strip optimization index, isWherein P is the buckling force of the elastic strip, delta is the elastic stroke of the elastic strip, m is the total mass of the elastic strip and sigma max The maximum stress of the elastic strip in the standard installation state is the energy stored per unit mass under the same stress level of the elastic strip in the standard installation state.
In the optimization process of the spring strip design, the larger the optimization index of the spring strip is, the more reasonable and economical the spring strip is designed. Taking the negative number of the bullet optimization index W as the objective function of the bullet optimization problem, the objective function of the bullet optimization problem is that
And re-calculating the calculated current approximate optimal solution in each current optimization subarea, and solving the current approximate optimal solution when the elastic strip optimization index is maximum in the standard installation state, wherein the current approximate optimal solution is the solved optimal solution.
According to the embodiment, the current approximate optimal solution is further screened, and the optimal solution of the current approximate optimal solution is obtained. Meanwhile, the calculated amount in the process of spring design is reduced, and the working efficiency in the design process is improved.
Fig. 2 shows a specific embodiment of the device for optimizing the design of the W-shaped spring strip according to the invention.
In this embodiment, the device for optimally designing a W-shaped spring strip mainly includes: the basic parameter obtaining module 201 is configured to obtain basic parameters of the elastic strip according to a spatial geometric relationship of the elastic strip, and assign a current parameter value and a current movement step length to the basic parameters according to a predetermined mechanism;
the intermediate data acquisition module 202 is configured to calculate a current optimized sub-area by using the current parameter value of each basic parameter and the current movement step length of each basic parameter, and a set of current numerical test results including a buckling force value, a maximum stress value, an inherent frequency value and a stored energy value of unit mass;
the current approximate optimization solution obtaining module 203 is configured to construct a current approximate constraint equation meeting the geometric form, the safety buckling pressure, the material yield strength, the excitation frequency range of the track response and the maximum energy stored in unit mass of the elastic strip according to the current numerical test result by using a regression analysis method, and solve the current approximate constraint equation in the current optimization subarea to obtain a current approximate optimization solution of the basic parameter; the method comprises the steps of,
the approximate solution judging module 204 is configured to determine the current approximate optimal solution as an approximate solution if the range of the current optimal sub-region is not greater than a predetermined range, obtain a next parameter value and a next movement step of the basic parameter according to a predetermined mechanism if the range of the current optimal sub-region is greater than the predetermined range, and calculate the next approximate optimal solution according to the next parameter value and the next movement step of the basic parameter;
the preset mechanism is to assign an initial parameter value and an initial movement step length to the basic parameter according to an empirical value, take a current approximate optimal solution as a next parameter value of the basic parameter, and calculate the next movement step length of the basic parameter according to the current approximate optimal solution and a last approximate optimal solution.
According to the specific embodiment, the design requirements of elastic strip stress, deformation and the like are met, the natural vibration frequency and modal characteristics of the elastic strip are considered, the elastic strip is automatically optimally designed, and the design and optimization efficiency of the elastic strip are greatly improved while the vibration performance of the elastic strip is improved.
In a specific embodiment of the present invention, the optimal design device of the elastic strip further includes an optimal solution judging module, configured to judge whether the approximate solution is an optimal solution according to a position of the approximate solution in the current optimization sub-region;
the optimal solution acquisition module is used for determining the approximate solution as an optimal solution if the approximate solution is not equal to the value at the endpoint of the current optimal sub-region;
and the recalculation module is used for obtaining the next parameter value and the next moving step length of the basic parameter according to a preset mechanism if the approximate solution is equal to the value at the endpoint of the current optimization subarea, and calculating the next approximate optimization solution according to the next parameter value and the next moving step length of the basic parameter.
In a specific embodiment of the present invention, each functional module in the bullet strip optimization design device of the present invention may be directly in hardware, in a software module executed by a processor, or in a combination of both.
A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium.
The processor may be a central processing unit (English: central Processing Unit; CPU; for short), or other general purpose processor, digital signal processor (English: digital Signal Processor; for short DSP), application specific integrated circuit (English: application Specific Integrated Circuit; ASIC; for short), field programmable gate array (English: field Programmable Gate Array; FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, etc. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.
The bullet strip optimizing design device provided by the invention can be used for executing the bullet strip optimizing design method described in any embodiment, and the implementation principle and the technical effect are similar, and are not repeated here.
In another embodiment of the present invention, a computer readable storage medium stores computer instructions operable to perform the method of optimizing the design of a spring in scenario one.
In the several embodiments provided by the present invention, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structural changes made by the present invention and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the present invention.
Claims (4)
1. An optimization design method of a spring strip is characterized by comprising the following steps of,
obtaining basic parameters of the elastic strip according to the space geometric relation of the elastic strip, and endowing the basic parameters with current parameter values and current moving step length according to a preset mechanism;
calculating a current optimization subarea by using the current parameter value of each basic parameter and the current moving step length of each basic parameter, and a group of current numerical test results comprising a buckling force value, a maximum stress value, an inherent frequency value and a stored energy value of unit mass;
constructing a current approximate constraint equation meeting the geometric form, the safety buckling force and the material yield strength of the elastic strip, the excitation frequency range of the track response and the maximum energy stored in unit mass according to the current numerical test result by using a regression analysis method, and solving the current approximate constraint equation in the current optimization subarea to obtain a current approximate optimization solution of the basic parameter, wherein the geometric constraint equation is established by using the regression analysis method according to the value in the current optimization subarea and the geometric form of the elastic strip so as to ensure that all parts of the elastic strip do not collide; according to the value in the current optimization subarea, the safe buckling pressure of the elastic strip and the material yield strength, a stress condition constraint equation is established by using the regression analysis method so as to ensure that the elastic strip meets a certain buckling pressure in a standard installation state and stress damage does not occur; establishing a natural frequency condition constraint equation by using the regression analysis method according to the value in the current optimization subarea and the excitation frequency range of the track response so as to ensure that the self-vibration frequency of the elastic strip in the standard installation state avoids the excitation frequency range of the track response; the method comprises the steps of,
if the range of the current optimization subarea is not larger than a preset range, determining the current approximate optimization solution as an approximate solution, and if the range of the current optimization subarea is larger than the preset range, obtaining a next parameter value and a next moving step length of the basic parameter according to the preset mechanism, and calculating the next approximate optimization solution according to the next parameter value and the next moving step length of the basic parameter;
the preset mechanism is to assign an initial parameter value and an initial movement step length to the basic parameter according to an empirical value, take the current approximate optimal solution as the next parameter value of the basic parameter, and calculate the next movement step length of the basic parameter according to the current approximate optimal solution and a last approximate optimal solution;
judging whether the approximate solution is an optimal solution according to the position of the approximate solution in the current optimization subarea;
if the approximate solution is not equal to the value at the endpoint of the current optimized sub-region, determining the approximate solution as the optimal solution;
and if the approximate solution is equal to the value at the endpoint of the current optimization subarea, obtaining the next parameter value and the next moving step length of the basic parameter according to the preset mechanism, and calculating the next approximate optimization solution according to the next parameter value and the next moving step length of the basic parameter.
2. The method for optimizing design of a spring strip according to claim 1, wherein the process of obtaining the basic parameters of the spring strip according to the space geometrical relationship of the spring strip comprises,
deducing the space position and space geometric dimension of the central axis of the elastic strip according to the structural view of the elastic strip;
and obtaining the basic parameters of the elastic strip according to the space position and the space geometric dimension of the central axis by using a parameterization equation.
3. An optimal design device of bullet strip, characterized by comprising:
the basic parameter acquisition module is used for obtaining basic parameters of the elastic strip according to the space geometric relation of the elastic strip, and endowing the basic parameters with current parameter values and current moving step lengths according to a preset mechanism;
the intermediate data acquisition module is used for calculating a current optimization subarea by utilizing the current parameter value of each basic parameter and the current moving step length of each basic parameter, and a group of current numerical test results comprising a buckling force value, a maximum stress value, an inherent frequency value and an energy value stored in unit mass;
the current approximate optimization solution acquisition module is used for constructing a current approximate constraint equation meeting the geometric form, the safety buckling pressure and the material yield strength of the elastic strip, the excitation frequency range of the track response and the maximum energy stored in unit mass according to the current numerical test result by using a regression analysis method, and solving the current approximate constraint equation in the current optimization subarea to obtain a current approximate optimization solution of the basic parameter, wherein the geometric constraint equation is established by using the regression analysis method according to the value in the current optimization subarea and the geometric form of the elastic strip so as to ensure that all parts of the elastic strip do not collide; according to the value in the current optimization subarea, the safe buckling pressure of the elastic strip and the material yield strength, a stress condition constraint equation is established by using the regression analysis method so as to ensure that the elastic strip meets a certain buckling pressure in a standard installation state and stress damage does not occur; establishing a natural frequency condition constraint equation by using the regression analysis method according to the value in the current optimization subarea and the excitation frequency range of the track response so as to ensure that the self-vibration frequency of the elastic strip in the standard installation state avoids the excitation frequency range of the track response; the method comprises the steps of,
an approximate solution judging module, configured to determine the current approximate optimal solution as an approximate solution if the range of the current optimal sub-region is not greater than a predetermined range, obtain a next parameter value and a next movement step size of the basic parameter according to the predetermined mechanism if the range of the current optimal sub-region is greater than the predetermined range, and calculate a next approximate optimal solution according to the next parameter value and the next movement step size of the basic parameter;
the preset mechanism is to assign an initial parameter value and an initial movement step length to the basic parameter according to an empirical value, take the current approximate optimal solution as the next parameter value of the basic parameter, and calculate the next movement step length of the basic parameter according to the current approximate optimal solution and a last approximate optimal solution;
the optimal solution judging module is used for judging whether the approximate solution is an optimal solution according to the position of the approximate solution in the current optimization subarea;
an optimized solution obtaining module, configured to determine the approximate solution as the optimal solution if the approximate solution is not equal to a value at an endpoint of the current optimized sub-region;
and the recalculation module is used for obtaining a next parameter value and a next moving step length of the basic parameter according to the preset mechanism if the approximate solution is equal to the value at the endpoint of the current optimization subarea, and calculating a next approximate optimization solution according to the next parameter value and the next moving step length of the basic parameter.
4. A computer readable storage medium storing computer instructions operable to perform the method of optimizing the design of a spring as claimed in any one of claims 1-2.
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