CN114074627A - Novel petal negative Poisson ratio bumper system and multidisciplinary optimization method thereof - Google Patents
Novel petal negative Poisson ratio bumper system and multidisciplinary optimization method thereof Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/18—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects characterised by the cross-section; Means within the bumper to absorb impact
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- B60R19/24—Arrangements for mounting bumpers on vehicles
- B60R19/26—Arrangements for mounting bumpers on vehicles comprising yieldable mounting means
- B60R19/34—Arrangements for mounting bumpers on vehicles comprising yieldable mounting means destroyed upon impact, e.g. one-shot type
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- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/18—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects characterised by the cross-section; Means within the bumper to absorb impact
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- B60—VEHICLES IN GENERAL
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- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/18—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects characterised by the cross-section; Means within the bumper to absorb impact
- B60R2019/186—Additional energy absorbing means supported on bumber beams, e.g. cellular structures or material
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Abstract
The invention discloses a novel petal negative Poisson ratio bumper system and a multidisciplinary optimization method thereof, and provides a novel bumper system based on a petal negative Poisson ratio material by combining the characteristics of light weight, high energy absorption characteristic and impact resistance of a negative Poisson ratio structure, wherein the system comprises a skin, an energy absorption block covering plate, a petal negative Poisson ratio energy absorption block, a beam covering plate, a petal negative Poisson ratio bumper beam and an energy absorption box; in addition, the macroscopic mechanical property of the bumper beam is realized by optimizing the microstructure parameters of the material, so that the damage to the legs of pedestrians is further reduced while the collision resistance of the original bumper beam is not changed, and the bumper system is compatible with the collision resistance and the pedestrian protection performance.
Description
Technical Field
The invention belongs to the technical field of vehicle collision safety, and particularly relates to a novel petal negative Poisson's ratio bumper system and a multidisciplinary optimization method thereof.
Background
In recent years, the number of traffic accidents is increased year by year with the increase of the automobile holding capacity in China, and irretrievable loss is brought to the life and property safety of people. The probability of different collision types in the traffic accident obtained according to the related statistical data is that when the traffic accident occurs to the automobile, the probability of the front collision is the largest and accounts for 40% of the total types.
When the vehicle is involved in a frontal collision, the bumper system located at the foremost end of the vehicle is the portion that collides with an object first. The system absorbs collision energy through the crushing deformation of the bumper beam and the energy absorption box, avoids the damage of impact force to the automobile body, and accordingly guarantees the safety of personnel in the automobile, and therefore the system has great significance in research of the front bumper system of the automobile in order to reduce the casualties in the automobile front collision accidents. Also based on this protective concept, early automotive bumper system research focused on the field of vehicle body safety, primarily to protect the vehicle body and occupants, and therefore bumper systems were often considered "harder is better".
With the continuous and deep research on automobile safety technology and the wide attention of people on pedestrian safety, the research on pedestrian protection has become one of the key research contents in the automobile safety technology field. According to investigation, in a body injury area in which pedestrian injury reaches or exceeds class 2 of simplified injury standard (AIS) in a traffic accident, the injury proportion of lower limbs is 34%, so that the pedestrian leg protection is an important part in the research field of pedestrian safety. In order to reduce the injury to pedestrians or other road users, more and more countries and organizations set out corresponding laws and regulations to guide the design work of automobile manufacturers. When a pedestrian collides with an automobile, a bumper system positioned at the front end of the automobile is directly contacted with legs of the pedestrian, so that the legs of the pedestrian are damaged, and therefore the safety performance of pedestrian protection is improved and the front bumper system of the automobile is required to be researched.
However, current research on bumper systems focuses primarily on low speed crashworthiness, such that the bumper systems must have sufficient stiffness and strength to protect body components and occupants of the vehicle during a collision. For pedestrians, the damage degree of the lower limbs of the pedestrians in the collision accident is increased by the fact that the rigidity of the bumper is too high. Therefore, a bumper system that combines impact resistance and pedestrian protection is highly desirable.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide a novel petal negative Poisson ratio bumper system and a multidisciplinary optimization method thereof, so as to solve the problem that the conventional bumper system is difficult to simultaneously consider both crashworthiness and pedestrian protection; the invention provides a novel petal negative Poisson ratio bumper system structure based on a negative Poisson ratio material by combining the characteristics of light weight, high energy absorption characteristic and impact resistance of the negative Poisson ratio structure, the macroscopic mechanical property of the novel petal negative Poisson ratio bumper system structure is realized by optimizing microstructure parameters of the material, and the damage to the legs of pedestrians is further reduced while the collision resistance of the original bumper beam is not changed.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the invention discloses a novel petal negative Poisson ratio bumper system, which comprises a skin, an energy absorption block covering plate, a petal negative Poisson ratio energy absorption block, a beam covering plate, a petal negative Poisson ratio bumper beam and an energy absorption box
The bumper beam is of a circular arc-shaped three-dimensional negative Poisson's ratio structure and is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, and two beam covering plates are welded on two longitudinal sides of the vehicle;
one beam cover plate in the longitudinal front of the vehicle is welded with the energy absorption block cover plate, and the other beam cover plate in the rear is welded with the front end of the energy absorption box;
the rear end of the energy absorption box is welded with a frame of a vehicle;
the beam energy absorption block is also of a three-dimensional negative Poisson's ratio structure in an arc shape and is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, but the whole size of the beam energy absorption block is smaller than that of a bumper beam, and two energy absorption block covering plates are welded on two longitudinal sides of the vehicle;
one energy absorption block covering plate in the longitudinal front of the vehicle is riveted with the skin, and the other energy absorption block covering plate in the rear is welded with the cross beam covering plate;
the beam energy absorption block is of a circular arc-shaped three-dimensional negative Poisson's ratio structure, is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, is arranged in a space between the bumper beam and the skin, is connected with the skin through rivets, and is welded with the bumper beam;
furthermore, the bumper beam and the beam covering plate are both made of aluminum alloy materials and are used for improving the collision resistance of the system; the beam energy absorption block and the energy absorption block mask are both made of polypropylene materials and are used for protecting pedestrians;
further, the bumper beam in the new bumper system has the same shape and dimensions as the rigid bumper beam of an existing vehicle;
in addition, the invention also provides a multidisciplinary optimization method of the novel bumper system, which comprises the following specific steps:
(1) establishing a novel bumper system finite element model, an automobile frontal collision finite element model, a pedestrian shank finite element model and a rigid wall finite element simulation model based on the ISIGHT software;
(2) determining parameters of the novel bumper system and performance evaluation indexes (namely optimization targets) of the system in collision with pedestrians and frontal collision;
(3) according to the system parameters and the evaluation indexes determined in the step (2), testing three levels of values of each parameter respectively, namely maximum variation, minimum variation and intermediate value to obtain test data, analyzing the sensitivity of each parameter, and selecting corresponding design variables;
(4) based on the optimization target and the design variable selection result in the step (3), adding the mass of the bumper as a light weight target, and establishing an approximate model between each optimization target and the design variable;
(5) establishing a novel bumper optimization model based on a multidisciplinary optimization method by combining the approximate model established in the step (4);
(6) and (3) building an optimization model through ISIGHT software, and carrying out parameter optimization on the novel bumper system based on the finite element model built in the step (1).
Further, the system parameters determined in the step (2) are: length of base side of unit cell of energy-absorbing block DabsAngle theta between single cell bottom edge and bevel edge of energy absorption blockabsUnit cell height H of energy absorption blockabsWall thickness T of unit cell of energy absorption blockabsSingle cell bottom side length D of bumper beambumAngle theta between single cell bottom edge and bevel edge of bumper beambumSingle cell wall thickness T of bumper beambumSingle cell diagonal length L of bumper beambum；
Further, the performance evaluation indexes under collision of the pedestrian in the step (2) are as follows: tibial maximum Acceleration (ACC)p) Maximum knee shear displacement (S)p) Knee maximum bend angle (Ben), pedestrian impact bumper system energy absorption (E)p) (ii) a The performance indexes under frontal collision are: driver seat down Acceleration (ACC)c) Longitudinal intrusion displacement (S) of the skinc) Rigid wall force (F)w) Energy absorption of the frontal impact bumper system (E)c)；
Further, the specific steps of the sensitivity analysis in the step (3) are as follows:
(31) and (3) carrying out sensitivity analysis on each parameter according to the performance index under pedestrian collision:
(311) respectively carrying out range analysis on the maximum tibial acceleration indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the maximum tibial acceleration, and determining corresponding design variable parameters;
(312) respectively carrying out range analysis on the maximum knee shearing displacement indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the maximum knee shearing displacement and determine corresponding design variable parameters;
(313) respectively carrying out range analysis on the maximum knee bending angle indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the maximum knee bending angle, and determining corresponding design variable parameters;
(314) respectively carrying out range analysis on the energy absorption indexes of the pedestrian collision bumper system by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the energy absorption of the pedestrian collision bumper system, and determining corresponding design variable parameters;
(315) selecting a common design variable parameter which can affect each performance index as a final design variable to be optimized;
(32) and (3) carrying out sensitivity analysis on each parameter according to the performance index under the frontal collision:
(321) performing range analysis on the acceleration indexes below the driver seat by the eight system parameters respectively to obtain the sequence of the sensitivity of the eight selected system parameters to the acceleration below the driver seat, and determining corresponding design variable parameters;
(322) respectively carrying out range analysis on the skin longitudinal invasion displacement indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the skin longitudinal invasion displacement, and determining corresponding design variable parameters;
(323) respectively carrying out range analysis on the acting force indexes of the rigid wall by the eight system parameters to obtain the sequence of the acting force sensitivity of the eight selected system parameters to the rigid wall, and determining corresponding design variable parameters;
(324) respectively carrying out range analysis on the energy absorption indexes of the bumper collision system by the eight system parameters to obtain the sequence of the energy absorption sensitivity of the bumper collision system by the eight selected system parameters, and determining corresponding design variable parameters;
(325) selecting a common design variable parameter which can affect each performance index as a final design variable to be optimized;
further, the approximate model between each optimization target and the design variable in the step (4) is established by using a second-order response surface method, and the specific model is as follows:
(41) approximate models of optimization targets under pedestrian collision:
approximate model of maximum acceleration of upper tibia:
the maximum shearing displacement of the knee joint is similar to the model:
the maximum bending angle of the knee joint is similar to the model:
approximate model of energy absorption of bumper system:
(42) approximate models of optimization targets under frontal collision:
driver seat below acceleration approximation model:
skin longitudinal intrusion displacement approximation model:
rigid wall acting force approximation model:
energy absorption of the frontal impact bumper system:
(43) approximate model of total mass of system:
further, the new bumper optimization model in step (5) is established by the following steps:
(51) the optimization design problem of the novel negative Poisson ratio bumper system is converted into a system-level optimization problem, the system-level optimization problem is split into a main system and two subsystems, and the main system optimization target is as follows: the comprehensive performance and the light weight of the bumper system are improved; the optimization objectives of the pedestrian collision subsystem and the frontal collision subsystem are respectively: pedestrian protection and frontal impact resistance;
(52) determining the coupling design variables of the design variables determined under pedestrian collision and the design variables determined under frontal collision;
(53) the different responses in the different subsystems are linked by the composite index f, which is expressed as:
wherein the weight value ω is ωe＝ωa＝0.5；E′0And E ″)0Energy absorption of the initially designed bumper system representing a pedestrian impact and a frontal impact, respectively; acc' and Acc "represent driver-seat-down accelerations of the initially designed bumper system for pedestrian and frontal collisions, respectively.
(54) The method comprises the following steps of taking comprehensive performance indexes and the mass of a negative Poisson ratio bumper as a main system optimization target, taking the variation range of all design variables of a novel bumper system, the knee shear displacement and the knee bending angle in pedestrian collision, the longitudinal invasion displacement of a skin and the acting force of a rigid wall in frontal collision, and the maximum difference value of all design variable ranges and coupling design variables in two subsystems as constraints, and constructing a main system optimization model:
in the formula, JpedAnd JcraOptimization objectives for the pedestrian collision subsystem and the frontal collision subsystem, respectively; epsilonpedAnd εcraSet convergence error thresholds for the pedestrian and frontal impact subsystems, respectively; d is the actual error; x 'and X' are initial values of X variable in the initially designed bumper system under pedestrian and frontal collisions, respectively, where X ═ Tabs，Tbum，Lbum，Habs]。
(55) Constructing an optimization model of a pedestrian collision subsystem and an optimization model of a frontal collision subsystem:
optimization model of pedestrian collision subsystem:
front collision subsystem optimization model:
further, the optimization step in the step (6) is as follows:
(61) building each optimization model in the ISIGHT software;
(62) subsystem optimization: optimizing the subsystems by adopting a T-distribution sparrow search algorithm (T-SSA) to obtain corresponding design variable optimization values in each subsystem, wherein the final results of the design variables except the coupled design variables are selected from the current optimization results;
(63) and (3) overall system optimization: and optimizing the coupling design variables by adopting a self-adaptive multi-objective particle swarm optimization AMOPSO to obtain coupling design variable optimized values, and selecting final coupling design variables in the coupling design variables to obtain final optimization results.
The invention has the beneficial effects that:
the invention designs a novel bumper system based on a negative Poisson ratio structure, further reduces the damage to the legs of pedestrians while not changing the collision resistance of the original bumper beam, and realizes the compatibility of the bumper system on the collision resistance and the pedestrian protection performance.
The invention adopts a multidisciplinary optimization method to optimize the structural parameters of the designed bumper system, meets the tendencies of each structural parameter to different performance indexes, further improves the comprehensive performance of the system and reduces the quality of the whole system.
Drawings
FIG. 1 is a schematic structural view of the novel bumper system of the present invention;
FIG. 2 is a flow chart of a hierarchical optimization method of the present invention.
Detailed Description
In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.
Referring to fig. 1, the novel petal negative poisson's ratio bumper system comprises a covering sheet, an energy absorption block covering plate, a petal negative poisson's ratio energy absorption block, a cross beam covering plate, a petal negative poisson's ratio bumper cross beam and an energy absorption box
The bumper beam is of a circular arc-shaped three-dimensional negative Poisson's ratio structure and is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, and two beam covering plates are welded on two longitudinal sides of the vehicle;
one beam cover plate in the longitudinal front of the vehicle is welded with the energy absorption block cover plate, and the other beam cover plate in the rear is welded with the front end of the energy absorption box;
the rear end of the energy absorption box is welded with a frame of a vehicle;
the beam energy absorption block is also of a three-dimensional negative Poisson's ratio structure in an arc shape and is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, but the whole size of the beam energy absorption block is smaller than that of a bumper beam, and two energy absorption block covering plates are welded on two longitudinal sides of the vehicle;
one energy absorption block covering plate in the longitudinal front of the vehicle is riveted with the skin, and the other energy absorption block covering plate in the rear is welded with the cross beam covering plate;
the beam energy absorption block is of a circular arc-shaped three-dimensional negative Poisson's ratio structure, is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, is arranged in a space between the bumper beam and the skin, is connected with the skin through rivets, and is welded with the bumper beam;
in a preferred embodiment, the bumper beam and the beam cover plate are both made of aluminum alloy materials and are used for improving the crashworthiness of the system; the beam energy absorption block and the energy absorption block mask are both made of polypropylene materials and are used for protecting pedestrians;
in a preferred embodiment, the bumper beam in the new bumper system has the same shape and dimensions as the rigid bumper beam of an existing vehicle;
referring to fig. 2, the invention further provides a multidisciplinary optimization method of the novel bumper system, which comprises the following specific steps:
(1) establishing a novel bumper system finite element model, an automobile frontal collision finite element model, a pedestrian shank finite element model and a rigid wall finite element simulation model based on the ISIGHT software;
(2) the parameters for determining the new bumper system are: length of base side of unit cell of energy-absorbing block DabsAngle theta between single cell bottom edge and bevel edge of energy absorption blockabsUnit cell height H of energy absorption blockabsWall thickness T of unit cell of energy absorption blockabsSingle cell bottom side length D of bumper beambumAngle theta between single cell bottom edge and bevel edge of bumper beambumSingle cell wall thickness T of bumper beambumSingle cell diagonal length L of bumper beambum(ii) a The performance evaluation indexes (namely optimization targets) of the system in collision with the pedestrian and frontal collision are as follows: tibial maximum Acceleration (ACC)p) Maximum knee shear displacement (S)p) Knee maximum bend angle (Ben), pedestrian impact bumper system energy absorption (E)p) (ii) a The performance indexes under frontal collision are: driver seat down Acceleration (ACC)c) Longitudinal intrusion displacement (S) of the skinc) Rigid wall force (F)w) Energy absorption of the frontal impact bumper system (E)c)；
(3) According to the system parameters and the evaluation indexes determined in the step (2), testing three levels of values of each parameter respectively, namely maximum variation, minimum variation and intermediate value to obtain test data, analyzing the sensitivity of each parameter, and selecting corresponding design variables, wherein the sensitivity analysis comprises the following specific steps:
(31) and (3) carrying out sensitivity analysis on each parameter according to the performance index under pedestrian collision:
(311) respectively carrying out range analysis on the maximum tibial acceleration indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the maximum tibial acceleration, and determining corresponding design variable parameters;
(312) respectively carrying out range analysis on the maximum knee shearing displacement indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the maximum knee shearing displacement and determine corresponding design variable parameters;
(313) respectively carrying out range analysis on the maximum knee bending angle indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the maximum knee bending angle, and determining corresponding design variable parameters;
(314) respectively carrying out range analysis on the energy absorption indexes of the pedestrian collision bumper system by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the energy absorption of the pedestrian collision bumper system, and determining corresponding design variable parameters;
(315) selecting a common design variable parameter which can affect each performance index as a final design variable to be optimized;
(32) and (3) carrying out sensitivity analysis on each parameter according to the performance index under the frontal collision:
(321) performing range analysis on the acceleration indexes below the driver seat by the eight system parameters respectively to obtain the sequence of the sensitivity of the eight selected system parameters to the acceleration below the driver seat, and determining corresponding design variable parameters;
(322) respectively carrying out range analysis on the skin longitudinal invasion displacement indexes by the eight system parameters to obtain the sequence of the sensitivity of the eight selected system parameters to the skin longitudinal invasion displacement, and determining corresponding design variable parameters;
(323) respectively carrying out range analysis on the acting force indexes of the rigid wall by the eight system parameters to obtain the sequence of the acting force sensitivity of the eight selected system parameters to the rigid wall, and determining corresponding design variable parameters;
(324) respectively carrying out range analysis on the energy absorption indexes of the bumper collision system by the eight system parameters to obtain the sequence of the energy absorption sensitivity of the bumper collision system by the eight selected system parameters, and determining corresponding design variable parameters;
(325) selecting a common design variable parameter which can affect each performance index as a final design variable to be optimized;
(4) based on the optimization target and the design variable selection result in the step (3), adding the mass of the bumper as a lightweight target, and establishing an approximate model between each optimization target and the design variable by adopting a second-order response surface method, wherein the specific model is as follows:
(41) approximate models of optimization targets under pedestrian collision:
approximate model of maximum acceleration of upper tibia:
the maximum shearing displacement of the knee joint is similar to the model:
the maximum bending angle of the knee joint is similar to the model:
approximate model of energy absorption of bumper system:
(42) approximate models of optimization targets under frontal collision:
driver seat below acceleration approximation model:
skin longitudinal intrusion displacement approximation model:
rigid wall acting force approximation model:
energy absorption of the frontal impact bumper system:
(43) approximate model of total mass of system:
(5) and (4) combining the approximate model established in the step (4), establishing a novel bumper optimization model based on a multidisciplinary optimization method, wherein the model establishment steps are as follows:
(51) the optimization design problem of the novel negative Poisson ratio bumper system is converted into a system-level optimization problem, the system-level optimization problem is split into a main system and two subsystems, and the main system optimization target is as follows: the comprehensive performance and the light weight of the bumper system are improved; the optimization objectives of the pedestrian collision subsystem and the frontal collision subsystem are respectively: pedestrian protection and frontal impact resistance;
(52) determining the coupling design variables of the design variables determined under pedestrian collision and the design variables determined under frontal collision;
(53) the different responses in the different subsystems are linked by the composite index f, which is expressed as:
wherein the weight value ω is ωe＝ωa＝0.5；E′0And E ″)0Energy absorption of the initially designed bumper system representing a pedestrian impact and a frontal impact, respectively; acc' and Acc "represent driver-seat-down accelerations of the initially designed bumper system for pedestrian and frontal collisions, respectively.
(54) The method comprises the following steps of taking comprehensive performance indexes and the mass of a negative Poisson ratio bumper as a main system optimization target, taking the variation range of all design variables of a novel bumper system, the knee shear displacement and the knee bending angle in pedestrian collision, the longitudinal invasion displacement of a skin and the acting force of a rigid wall in frontal collision, and the maximum difference value of all design variable ranges and coupling design variables in two subsystems as constraints, and constructing a main system optimization model:
in the formula, JpedAnd JcraOptimization objectives for the pedestrian collision subsystem and the frontal collision subsystem, respectively; epsilonpedAnd εcraSet convergence error thresholds for the pedestrian and frontal impact subsystems, respectively; d is the actual error; x 'and X' are initial values of X variable in the initially designed bumper system under pedestrian and frontal collisions, respectively, where X ═ Tabs，Tbum，Lbum，Habs]。
(55) Constructing an optimization model of a pedestrian collision subsystem and an optimization model of a frontal collision subsystem:
optimization model of pedestrian collision subsystem:
front collision subsystem optimization model:
(6) an optimization model is built through ISIGHT software, parameter optimization of the novel bumper system is carried out based on the finite element model built in the step (1), and the optimization steps are as follows:
(61) building each optimization model in the ISIGHT software;
(62) subsystem optimization: optimizing the subsystems by adopting a T-distribution sparrow search algorithm (T-SSA) to obtain corresponding design variable optimization values in each subsystem, wherein the final results of the design variables except the coupled design variables are selected from the current optimization results;
(63) and (3) overall system optimization: and optimizing the coupling design variables by adopting a self-adaptive multi-objective particle swarm optimization AMOPSO to obtain coupling design variable optimized values, and selecting final coupling design variables in the coupling design variables to obtain final optimization results.
While the invention has been described in terms of its preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims (8)
1. A novel petal negative Poisson ratio bumper system is characterized by comprising a covering sheet, an energy absorption block covering plate, a petal negative Poisson ratio energy absorption block, a beam covering plate, a petal negative Poisson ratio bumper beam and an energy absorption box
The bumper beam is of a circular arc-shaped three-dimensional negative Poisson's ratio structure and is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, and two beam covering plates are welded on two longitudinal sides of the vehicle;
one beam cover plate in the longitudinal front of the vehicle is welded with the energy absorption block cover plate, and the other beam cover plate in the rear is welded with the front end of the energy absorption box;
the rear end of the energy absorption box is welded with a frame of a vehicle;
the beam energy absorption block is also of a three-dimensional negative Poisson's ratio structure in an arc shape and is formed by periodically and regularly arranging a large number of petal cellular structures with the same structural direction, but the whole size of the beam energy absorption block is smaller than that of a bumper beam, and two energy absorption block covering plates are welded on two longitudinal sides of the vehicle;
one energy absorption block covering plate in the longitudinal front of the vehicle is riveted with the skin, and the other energy absorption block covering plate in the rear is welded with the cross beam covering plate;
the beam energy absorption block is a circular arc-shaped three-dimensional negative Poisson's ratio structure, is formed by periodically and regularly arranging a large number of inner petal cellular structures with the same structural direction, is arranged in a space between the bumper beam and the skin, is connected with the skin through rivets, and is welded with the bumper beam.
2. The novel petal negative Poisson's ratio bumper system of claim 1, wherein said bumper beam and beam cover plate are both made of aluminum alloy material for improved system crashworthiness; the beam energy absorption block and the energy absorption block mask are both made of polypropylene materials and are used for protecting pedestrians.
3. The novel petal negative Poisson's ratio bumper system according to claim 2, wherein the bumper beam in the novel petal negative Poisson's ratio bumper system has the same shape and dimensions as the rigid bumper beam of an existing vehicle.
4. A multidisciplinary optimization method of a novel petal negative poisson ratio bumper system, which is based on the system of any one of claims 1-3 and is characterized by comprising the following steps:
(1) establishing a novel petal negative Poisson ratio bumper system finite element model, an automobile frontal collision finite element model, a pedestrian shank finite element model and a rigid wall finite element simulation model based on ISIGHT software;
(2) determining parameters of a novel petal negative Poisson ratio bumper system and performance evaluation indexes (namely optimization targets) of collision and frontal collision of the system with pedestrians;
(3) according to the system parameters and the evaluation indexes determined in the step (2), testing three levels of values of each parameter respectively, namely maximum variation, minimum variation and intermediate value to obtain test data, analyzing the sensitivity of each parameter, and selecting corresponding design variables;
(4) based on the optimization target and the design variable selection result in the step (3), adding the mass of the bumper as a light weight target, and establishing an approximate model between each optimization target and the design variable;
(5) establishing a novel bumper optimization model based on a multidisciplinary optimization method by combining the approximate model established in the step (4);
(6) and (3) building an optimization model through ISIGHT software, and carrying out parameter optimization on the novel petal negative Poisson's ratio bumper system based on the finite element model built in the step (1).
5. The multidisciplinary optimization method for a novel petal negative Poisson's ratio bumper system according to claim 4, wherein the system parameters determined in the step (2) are: length of base side of unit cell of energy-absorbing block DabsAngle theta between single cell bottom edge and bevel edge of energy absorption blockabsUnit cell height H of energy absorption blockabsWall thickness T of unit cell of energy absorption blockabsSingle cell bottom side length D of bumper beambumAngle theta between single cell bottom edge and bevel edge of bumper beambumSingle cell wall thickness T of bumper beambumSingle cell diagonal length L of bumper beambum(ii) a The performance evaluation indexes under pedestrian collision are as follows: tibial maximum Acceleration (ACC)p) Maximum knee shear displacement (S)p) Knee maximum bend angle (Ben), pedestrian impact bumper system energy absorption (E)p) (ii) a The performance indexes under frontal collision are: driver seat down Acceleration (ACC)c) Longitudinal intrusion displacement (S) of the skinc) Rigid wall force (F)w) Energy absorption of the frontal impact bumper system (E)c)。
6. The multidisciplinary optimization method for the novel petal negative Poisson's ratio bumper system as claimed in claim 5, wherein the approximate model between each optimization target and the design variable in the step (4) is established by a second-order response surface method, and the specific model is as follows:
(41) approximate models of optimization targets under pedestrian collision:
approximate model of maximum acceleration of upper tibia:
the maximum shearing displacement of the knee joint is similar to the model:
the maximum bending angle of the knee joint is similar to the model:
approximate model of energy absorption of bumper system:
(42) approximate models of optimization targets under frontal collision:
driver seat below acceleration approximation model:
skin longitudinal intrusion displacement approximation model:
rigid wall acting force approximation model:
energy absorption of the frontal impact bumper system:
(43) approximate model of total mass of system:
7. the multidisciplinary optimization method for the novel petal negative Poisson's ratio bumper system as claimed in claim 6, wherein the novel bumper optimization model in the step (5) is established by the following steps:
(51) the optimization design problem of the novel petal negative Poisson ratio bumper system is converted into a system-level optimization problem, the system-level optimization problem is split into a main system and two subsystems, and the main system optimization target is as follows: the comprehensive performance and the light weight of the bumper system are improved; the optimization objectives of the pedestrian collision subsystem and the frontal collision subsystem are respectively: pedestrian protection and frontal impact resistance;
(52) determining the coupling design variables of the design variables determined under pedestrian collision and the design variables determined under frontal collision;
(53) the different responses in the different subsystems are linked by the composite index f, which is expressed as:
wherein the weight value ω is ωe＝ωa＝0.5；E′0And E ″)0Energy absorption of the initially designed bumper system representing a pedestrian impact and a frontal impact, respectively; acc' and Acc "represent driver-seat-down accelerations of the initially designed bumper system for pedestrian and frontal collisions, respectively.
(54) The method comprises the following steps of taking comprehensive performance indexes and the mass of a negative poisson ratio bumper as a main system optimization target, taking the variation range of all design variables of a novel petal negative poisson ratio bumper system, knee shear displacement and knee bending angle in pedestrian collision, skin longitudinal invasion displacement and rigid wall acting force in frontal collision, and the maximum difference value of all design variable ranges and coupling design variables in two subsystems as constraints, and constructing a main system optimization model:
in the formula, JpedAnd JcraOptimization objectives for the pedestrian collision subsystem and the frontal collision subsystem, respectively; epsilonpedAnd εcraSet convergence error thresholds for the pedestrian and frontal impact subsystems, respectively; d is the actual error; x 'and X' are initial values of X variable in the initially designed bumper system under pedestrian and frontal collisions, respectively, where X ═ Tabs，Tbum，Lbum，Habs]。
(55) Constructing an optimization model of a pedestrian collision subsystem and an optimization model of a frontal collision subsystem:
optimization model of pedestrian collision subsystem:
front collision subsystem optimization model:
8. the multidisciplinary optimization method for a novel petal negative Poisson's ratio bumper system according to claim 7, wherein the optimization step in the step (6) is as follows:
(61) building each optimization model in the ISIGHT software;
(62) subsystem optimization: optimizing the subsystems by adopting a T-distribution sparrow search algorithm (T-SSA) to obtain corresponding design variable optimization values in each subsystem, wherein the final results of the design variables except the coupled design variables are selected from the current optimization results;
(63) and (3) overall system optimization: and optimizing the coupling design variables by adopting a self-adaptive multi-objective particle swarm optimization AMOPSO to obtain coupling design variable optimized values, and selecting final coupling design variables in the coupling design variables to obtain final optimization results.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115481493A (en) * | 2022-10-10 | 2022-12-16 | 南京林业大学 | Variable-cross-section long glass fiber reinforced polypropylene bumper beam optimization method based on crashworthiness |
| CN117195639A (en) * | 2023-09-12 | 2023-12-08 | 中航成飞民用飞机有限责任公司 | Structure bird strike resistance evaluation method based on energy dissipation path |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106184085A (en) * | 2016-06-30 | 2016-12-07 | 南京航空航天大学 | A kind of closed loop negative poisson's ratio construction car security system and method for designing |
| CN106570255A (en) * | 2016-10-27 | 2017-04-19 | 南京航空航天大学 | Optimization method of negative Poisson ratio energy absorption structure based on pedestrian protection |
| CN106997417A (en) * | 2017-04-28 | 2017-08-01 | 南京航空航天大学 | A kind of automatic buffer energy-absorbing A posts and its optimization method based on pedestrian protecting |
| CN107235024A (en) * | 2017-04-28 | 2017-10-10 | 南京航空航天大学 | A kind of Varying-thickness gradient negative poisson's ratio automatic buffer endergonic structure and its optimization method |
-
2021
- 2021-10-14 CN CN202111200573.5A patent/CN114074627A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106184085A (en) * | 2016-06-30 | 2016-12-07 | 南京航空航天大学 | A kind of closed loop negative poisson's ratio construction car security system and method for designing |
| CN106570255A (en) * | 2016-10-27 | 2017-04-19 | 南京航空航天大学 | Optimization method of negative Poisson ratio energy absorption structure based on pedestrian protection |
| CN106997417A (en) * | 2017-04-28 | 2017-08-01 | 南京航空航天大学 | A kind of automatic buffer energy-absorbing A posts and its optimization method based on pedestrian protecting |
| CN107235024A (en) * | 2017-04-28 | 2017-10-10 | 南京航空航天大学 | A kind of Varying-thickness gradient negative poisson's ratio automatic buffer endergonic structure and its optimization method |
Non-Patent Citations (1)
| Title |
|---|
| 王崴崴: ""新型负泊松比保险杠系统多学科优化设计"", 《中国优秀硕士学位论文全文数据库工程科技II辑》, pages 14 - 60 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115481493A (en) * | 2022-10-10 | 2022-12-16 | 南京林业大学 | Variable-cross-section long glass fiber reinforced polypropylene bumper beam optimization method based on crashworthiness |
| CN115481493B (en) * | 2022-10-10 | 2024-04-30 | 南京林业大学 | Variable-section long glass fiber reinforced polypropylene bumper beam optimization method based on crashworthiness |
| CN117195639A (en) * | 2023-09-12 | 2023-12-08 | 中航成飞民用飞机有限责任公司 | Structure bird strike resistance evaluation method based on energy dissipation path |
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