CN110046416A - A kind of finite element method of the tools for bolts ' pretension state change under action of lateral load - Google Patents
A kind of finite element method of the tools for bolts ' pretension state change under action of lateral load Download PDFInfo
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Abstract
The present invention relates to a kind of finite element methods of tools for bolts ' pretension state change under action of lateral load.The following steps are included: S1: establishing thread connection finite element mesh model in Hypermesh software；S2: setting material parameter；S3: model file is saved and is imported in Abaqus software；S4: creation screw thread engagement contact to and nuts contact with clamped part pair；S5: three analysis steps are defined；S6: three reference points are established；S7: six-freedom degree is defined respectively to bolt, nut and each reference point；S8: field output is defined；S9: setting boundary condition；S10: the state change that nuts is contacted with clamped part is extracted.The main reason for present invention is by loosening thread connection in actual condition-action of lateral load carries out simulation analysis, it obtains being threadably coupled within the corner variation that action of lateral load contacts the variation of Pre strained state in the process, tangential force is moved back with lateral displacement variation and nuts generation pine, computational efficiency is improved, saves and calculates the time.
Description
Technical field
The present invention relates to finite element simulation technical fields, and in particular to one kind tools for bolts ' pretension state under action of lateral load
The finite element method of variation.
Background technique
Thread connection is one of most common and most widely used type of attachment, precision height, warp convenient with assembly and disassembly
The advantages that Ji property is good.Therefore the reliability of thread connection is particularly important, especially under vibration, because the factors such as loosening cause
Thread connection failure leads to structure abnormal sound, even results in thread joined structure so as to cause the decline of pressing force suffered by clamped part
Fatigue fracture etc. causes major accident.As shown in Figure 1, nuts shows with clamped part contact surface state change when being bolt-connection
It is intended to, close-coupled that both black state is, both the grid-like state of grey, which is, is slidably connected, it can be seen that with using the time
Passage, pretightning force between the two is smaller and smaller, and last pretightning force disappears, and the two connection pine drags.
Finite element analysis (Finite Element Analysis), abbreviation FEA is developed rapidly in modern computer
On the basis of and a kind of numerical approximation method for growing up, it is to solve object with the unit of many interactions of composition model
Come replace directly to complex model solve, to realize the simplification of challenge, but be not Exact Solutions by the solution that it is acquired, and
It is a kind of approximate solution.In practical applications, many models, operating condition are excessively complicated, or even can not estimate, but finite element analysis side
Method is widely applicable, in recent years again constantly update and compensatory algorithm, have become solve engineering problem and analysis important means.
Many researchs are had been carried out to thread connection currently with finite element method, but for a long time due to screw thread
The complexity of coupling structure lacks always unified understanding for the loosening mechanism of thread connection, but existing research shows transverse direction
Oscillating load is the main reason for caused thread connection loosens.
Summary of the invention
Against the above deficiency, the present invention provides a kind of finite elements of tools for bolts ' pretension state change under action of lateral load
Analysis method, this method disclose transverse load pair from contact relation and tangential force two angles of variation between thread connection component
The influence that thread connection loosens solves the problems, such as that existing thread connection loosens.
The technical solution of the present invention is as follows:
A kind of finite element method of the tools for bolts ' pretension state change under action of lateral load, comprising the following steps:
S1: establishing thread connection finite element mesh model in Hypermesh software, and the model includes one clamped
Part, a bolt and an attaching nut；
S2: setting material parameter, including density of material, Young's modulus, Poisson's ratio, and material properties are assigned for each part；
S3: model file is saved and is imported in Abaqus software；
S4: creation screw thread engagement contact to and nuts contact with clamped part pair；
S5: three analysis steps, respectively step1, step2 and step3 are defined；
S6: establishing three reference points, respectively RP-Plate, RP-Bolt, RP-Nut, the reference point RP-Plate with
Clamped part bottom surface node makees movement coupling constraint, and the reference point RP-Bolt is transported with nuts cylindrical outer surface node
Dynamic coupling constraint, the reference point RP-Nut and nut cylindrical outer surface node make movement coupling constraint；
S7: defining six-freedom degree to bolt, nut and each reference point respectively, is respectively as follows: displacement along the x axis, along Y
Axis direction displacement, along Z-direction displacement, turn about the X axis angle, around Y-axis rotational angle, turn about the Z axis angle；
S8: field output is defined, the tangential friction force that course output nuts contact pair with clamped part, course, which exports, to be referred to
Point RP-Bolt's turns about the X axis angle；
S9: setting boundary condition: the constraint to symmetry class of the bolt setting since initial step only discharges X-direction
Displacement freedom remains unchanged when being displaced along the x axis from step1 to step2, and when step3 selects failure mode；To reference point
The constraint of displacement type of the RP-Plate setting since initial step, and six-freedom degree is discharged, six-freedom degree value is in step1
When be disposed as remaining unchanged when 0, step2, will modification of displacement be along the y axis lateral displacement load amplitude when step3, and select
Sinusoidal load mode is selected, other freedom degrees maintain 0 value constant；Displacement type since step1 is arranged to reference point RP-Nut
Constraint, and discharge six-freedom degree, six-freedom degree value is disposed as 0 in step1, and when step2, step3 keeps not
Become；
S10: extracting the state change that nuts is contacted with clamped part, using lateral displacement load as abscissa, ordinate
The tangential friction force for exporting nuts and clamped part contact surface, using the time as abscissa, ordinate exports reference point RP-Bolt
Turn about the X axis angle.
The thread connection mesh of finite element model established in the step S1 is the hexahedron network mould for considering lead angle
Type.
The tangential behavior contacted in the step S4 is all made of penalty function friction model algorithm.
In the normal direction behavior contacted in the step S4, screw thread engagement contact uses the soft Contact Algorithm of exponential form, spiral shell
Bolt cap contacts the hard Contact Algorithm using penalty function with clamped part.
The present invention is from the contact relation and tangential force two angles of variation between thread connection component, by actual condition
The main reason for thread connection loosens-action of lateral load carries out simulation analysis, to observe it to threaded pre-tightening state change
It influences.The present invention accounts for the fine modeling of lead angle to screw thread as a result, and introduces the thought of interaction, by setting
Setting boundary condition reduces contact creation logarithm, can be obtained and contacts Pre strained state during being threadably coupled within action of lateral load
Variation, tangential force changes with lateral displacement and nuts occurs the corner that moves back of pine and changes, improve computational efficiency, save and calculate
Time.Meanwhile the present invention can be in simulating other similar bolt looseness problems as reference.
Detailed description of the invention
Fig. 1 is that the nuts of the embodiment of the present invention and clamped part contact condition change schematic diagram；
Fig. 2 is the model structure and reference point schematic diagram of the embodiment of the present invention；
Fig. 3 is nuts constraint and the reference point coupling constraint schematic diagram of the embodiment of the present invention；
Fig. 4 is the tangential force of the embodiment of the present invention with lateral displacement load change relation schematic diagram；
Fig. 5 is the nuts pine retreat angle variation schematic diagram of the embodiment of the present invention.
Specific embodiment
It is described further below with reference to technical effect of the attached drawing to design of the invention, specific structure and generation, with
It is fully understood from the purpose of the present invention, feature and effect.
Referring to figs. 2 and 3, the finite element analysis side of the tools for bolts ' pretension state change of the invention under action of lateral load
Method, comprising the following steps:
S1: establishing thread connection finite element mesh model in Hypermesh software, and model includes a clamped part
10, a M16 plain bolt 20 and an attaching nut 30, clamped part 10 are spun on the screw rod of bolt 20, and side resists spiral shell
Bolt cap, the other side are clamped with nut 30, and grid model is the hexahedron network model for considering lead angle；
S2: setting material parameter, including density of material, Young's modulus, Poisson's ratio, and material properties are assigned for each part；
S3: model file is saved as into .inp file, and is imported in Abaqus software；
S4: creation screw thread engagement contact to and nuts contact with clamped part pair, the tangential behavior of contact, which is all made of, penalizes
Function friction model algorithm, in the normal direction behavior of contact, screw thread engagement contact uses the soft Contact Algorithm of exponential form, nuts
The hard Contact Algorithm using penalty function is contacted with clamped part；
S5: three analysis steps, respectively step1, step2 and step3 are defined；
S6: three reference points, respectively RP-Plate11, RP-Bolt21, RP-Nut31, reference point RP- are established
Plate11 and clamped 10 bottom surface node of part make movement coupling constraint, reference point RP-Bolt21 and 20 cap cylinder appearance of bolt
Face node makees movement coupling constraint, and reference point RP-Nut31 and 30 cylindrical outer surface node of nut make movement coupling constraint；
S7: defining six-freedom degree U1, U2, U3, UR1, UR2, UR3 to bolt 20, nut 30 and each reference point respectively,
Displacement along the x axis is respectively represented, is displaced along the y axis, is displaced along Z-direction, turns about the X axis angle, around Y-axis angle of rotation
It spends, turn about the Z axis angle；
S8: field output is defined, the tangential friction force that course output nuts contact pair with clamped part, course, which exports, to be referred to
Point RP-Bolt21's turns about the X axis angle UR1；
S9: setting boundary condition:
The constraint for the symmetry class that initial step starts is set to bolt 20, only discharges X-direction displacement freedom, i.e. edge
X-direction is displaced U1 ≠ 0, and U1 is remained unchanged when from step1 to step2, is U1 selection failure mould when brought forward value, step3
Formula；
Constraint to displacement type of the reference point RP-Plate11 setting since initial step, and six-freedom degree is discharged,
Six-freedom degree value is disposed as 0, i.e. U1=U2=U3=UR1=UR2=UR3=0 in step1, and when step2 keeps not
Become, is revised as lateral displacement load amplitude for U2 will be displaced along the y axis when brought forward value, step3, and select sinusoidal load mould
Formula, other freedom degrees maintain 0 value constant；
The constraint of displacement type since step1 is set to reference point RP-Nut31, and discharges six-freedom degree, six
Free angle value is disposed as 0, i.e. U1=U2=U3=UR1=UR2=UR3=0 in step1, and when step2, step3 keeps
It is constant, for after brought forward value；
S10: the state change that nuts is contacted with clamped part is extracted: as shown in figure 4, with lateral displacement load for horizontal seat
Mark, ordinate export the tangential friction force of nuts and clamped part contact surface, reflect lateral displacement load to bolt pretightening
Influence.As shown in figure 5, using the time as abscissa, ordinate exports the axial corner of reference point RP-Bolt, reflection with when
Between elapse, nuts pine retreat angle variation.
The present invention can concisely obtain being threadably coupled within action of lateral load mistake based on screw thread refined model
The tangential force of the variation of contact condition in journey, nuts and clamped part contact surface changes with lateral displacement, and and nuts
The variation that pine retreat angle occurs, improves computational efficiency, saves and calculates the time.
Disclosed above is only the embodiment of the present invention, and still, the present invention is not limited to this, the technology of any this field
What personnel can think variation should all fall into protection scope of the present invention.
Claims (4)
1. a kind of finite element method of the tools for bolts ' pretension state change under action of lateral load, which is characterized in that including with
Lower step:
S1: establishing thread connection finite element mesh model in Hypermesh software, and the model includes a clamped part
(10), a bolt (20) and an attaching nut (30)；
S2: setting material parameter, including density of material, Young's modulus, Poisson's ratio, and material properties are assigned for each part；
S3: model file is saved and is imported in Abaqus software；
S4: creation screw thread engagement contact to and nuts contact with clamped part pair；
S5: three analysis steps, respectively step1, step2 and step3 are defined；
S6: three reference points, respectively RP-Plate (11), RP-Bolt (21), RP-Nut (31), the reference point RP- are established
Plate (11) and clamped part (10) bottom surface node make movement coupling constraint, the reference point RP-Bolt (21) and bolt
(20) cap cylindrical outer surface node makees movement coupling constraint, the reference point RP-Nut (31) and nut (30) cylindrical outer surface section
Point makees movement coupling constraint；
S7: six-freedom degree is defined to bolt (20), nut (30) and each reference point respectively, is respectively as follows: position along the x axis
Move, along the y axis displacement, along Z-direction displacement, turn about the X axis angle, around Y-axis rotational angle, turn about the Z axis angle；
S8: field output, the tangential friction force that course output nuts contacts pair with clamped part, course output reference point are defined
RP-Bolt's (21) turns about the X axis angle；
S9: setting boundary condition: the constraint to symmetry class of bolt (20) setting since initial step only discharges X-direction
Displacement freedom remains unchanged when being displaced along the x axis from step1 to step2, and when step3 selects failure mode；
Constraint to displacement type of reference point RP-Plate (11) setting since initial step, and six-freedom degree is discharged, six
A free angle value remains unchanged when being disposed as 0, step2 in step1, will modification of displacement be along the y axis laterally when step3
It is displaced load amplitude, and selects sinusoidal load mode, other freedom degrees maintain 0 value constant；Reference point RP-Nut (31) are arranged
The constraint of displacement type since step1, and six-freedom degree is discharged, six-freedom degree value is disposed as 0 in step1,
It is remained unchanged when step2, step3；
S10: extracting the state change that nuts is contacted with clamped part, using lateral displacement load as abscissa, ordinate output
The tangential friction force of nuts and clamped part contact surface, using the time as abscissa, ordinate exports reference point RP-Bolt (21)
Turn about the X axis angle.
2. finite element method according to claim 1, which is characterized in that the thread connection established in the step S1
Mesh of finite element model is the hexahedron network model for considering lead angle.
3. finite element method according to claim 1, which is characterized in that the tangential behavior contacted in the step S4
It is all made of penalty function friction model algorithm.
4. finite element method according to claim 1, which is characterized in that the normal direction behavior contacted in the step S4
On, screw thread engagement contact uses the soft Contact Algorithm of exponential form, and nuts contacts connecing firmly using penalty function with clamped part
Touch algorithm.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910277741.7A CN110046416B (en) | 2019-04-08 | 2019-04-08 | Finite element analysis method for bolt pre-tightening state change under transverse load effect |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910277741.7A CN110046416B (en) | 2019-04-08 | 2019-04-08 | Finite element analysis method for bolt pre-tightening state change under transverse load effect |
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| CN110046416B CN110046416B (en) | 2023-07-18 |
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| CN112052510A (en) * | 2019-12-12 | 2020-12-08 | 格特拉克（江西）传动系统有限公司 | Method for checking slip risk of bolted connection of differential mechanism based on dynamic load |
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| CN113886984A (en) * | 2021-09-28 | 2022-01-04 | 中国第一汽车股份有限公司 | Bolt solid grid modeling and loading method |
| CN113886984B (en) * | 2021-09-28 | 2022-09-09 | 中国第一汽车股份有限公司 | Bolt solid grid modeling and loading method |
| CN117390914A (en) * | 2023-09-25 | 2024-01-12 | 航天精工股份有限公司 | Connection system looseness finite element simulation method considering thread creep |
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