CN105631153A - Predicting and controlling method for wrinkling of stamping parts - Google Patents

Abstract

The invention discloses a predicting and controlling method for wrinkling of stamping parts. The predicting and controlling method comprises the following steps of S1, selecting a plurality of stamping parts with similar structural characteristics as analysis samples; S2, decomposing similar structural characteristics of all the stamping parts to obtain structural characteristic elements for forming the similar structural characteristics of all the stamping parts and the quantity of all the structural characteristic elements; S3, simulating forming processes of all the stamping parts to obtain wrinkle values of all the stamping parts; S4, establishing a wrinkling principle; S5, constructing a wrinkling prediction model based on the structural characteristic elements; S6, plugging the wrinkling values of all the stamping parts in the step S3 into the wrinkling prediction model to obtain the relationship among all structural characteristic element coefficients, and weakening or enhancing the corresponding structural characteristic elements during product design according to the relationship, thus controlling the generation of wrinkles. According to the predicting and controlling method disclosed by the invention, the wrinkling risk of the stamping parts can be simply and conveniently calculated, the wrinkling of the stamping parts is quickly predicted, and further the aim of prejudging the wrinkling of the stamping parts in a design stage is achieved.

Description

Prediction that a kind of stamping parts is wrinkling and control method

Technical field

The invention belongs to stamping technology field, particularly relate to the wrinkling prediction of a kind of stamping parts and control method.

Background technology

In actual production, stamping parts there will be wrinkling, and this makes the dimensional accuracy of stamping parts be forbidden, surface quality is bad, thus affecting assembly precision and product appearance; And, the wrinkling solder joint distortion being also easily caused in stamping parts welding process of stamping parts and solder joint ftracture; It addition, because wrinkling place material is by relatively huge pressing stress, so can take the lead in when stamping parts (mostly being the heat-punch member for auto parts and components) bearing load producing fatigue failure and then causing fracture.

What stamping parts was wrinkling produces the impact by various factors, for instance the geometry of the material property of metal blank, part and mould and other technological parameter including pressure-pad-force, lubricating status etc. Finding from practical condition, the geometrical factor of part or die face is to cause wrinkling key. Therefore, the application proposes a kind of angle from punching parts architectural feature and goes out to send prediction and control the wrinkling method of punching parts.

Summary of the invention

It is an object of the invention to provide the wrinkling prediction of a kind of stamping parts and control method, it predicts wrinkling by setting up the wrinkling forecast model based on architectural feature key element, the wrinkling risk of stamping parts can be calculated simply and easily, fast prediction stamping parts is wrinkling, and then reaches in the design phase the wrinkling purpose carrying out anticipation to stamping parts.

The technical solution adopted for the present invention to solve the technical problems is:

The wrinkling prediction of a kind of stamping parts and control method are provided, comprise the following steps:

S1, choose the multiple stamping parts with similar structural characteristics as analyzing sample;

S2, shape according to similar structural characteristics, decompose the similar structural characteristics of each stamping parts, obtain constituting the architectural feature key element 1 of each stamping parts similar structural characteristics, 2,3 ..., n, and the quantity n of each architectural feature key element_i, i=(1,2,3 ..., n), the architectural feature key element that each stamping parts comprises has certain intercrossing, all architectural feature key elements of induction-arrangement;

S3, set up the punching press FEM (finite element) model of each stamping parts, simulate the forming process of each stamping parts, obtain the wrinkling value of each stamping parts;

S4, set up wrinkling criterion: the stress-strain relation of each stamping parts is

$\left.\begin{array}{c}{\mathrm{\ϵ}}_1=\frac{{\mathrm{\ϵ}}_i}{{\mathrm{\σ}}_i}\left({\mathrm{\σ}}_1-\frac{R}{1+R}{\mathrm{\σ}}_2\right)\\ {\mathrm{\ϵ}}_2=\frac{{\mathrm{\ϵ}}_i}{{\mathrm{\σ}}_i}\left({\mathrm{\σ}}_2-\frac{R}{1+R}{\mathrm{\σ}}_1\right)\\ {\mathrm{\ϵ}}_t=\frac{{\mathrm{\ϵ}}_i}{{\mathrm{\σ}}_i}\frac{{\mathrm{\σ}}_1+{\mathrm{\σ}}_2}{1+R}\end{array}\right\}---\left(1\right),$

Wherein, ��₁It is plane principal strain, ��₂It is plane time strain, ��_tBeing perpendicular to the principal strain in direction, plate face, R is average the coefficient of normal anisortopy, ��_iIt is equivalent strain, ��_iIt it is equivalent stress;

Compressive stress owing to being parallel to plate face causes wrinkling, therefore the generation of wrinkle and secondary stress ��₂Relevant, obtain according to formula (1)

${\mathrm{\σ}}_2=\mathrm{\λ}({\mathrm{\ϵ}}_2+\frac{R}{R+1}{\mathrm{\ϵ}}_1)---\left(2\right),$

Wherein,Work as ��₂When=0, plate is in unidirectional tension state, is occur with the form of uniaxial tension line in forming limit diagram, using this uniaxial tension line as substantially wrinkling criterion, it is considered to the loading history impact on wrinkling impact and geometry size, obtains wrinkling criterion

${\mathrm{\ϵ}}_{wc}=\mathrm{\ρ}\{max\[-({\mathrm{\ϵ}}_2+\frac{R}{R+1}{\mathrm{\ϵ}}_1),0\]-min\[-({\mathrm{\ϵ}}_2+\frac{R}{R+1}{\mathrm{\ϵ}}_1),0\]\}---\left(3\right),$

Wherein, �� is the coefficient relevant with curvature, ��_wc>=0, work as ��_wcWhen=0, plate, without wrinkling, works as ��_wcDuring > 0, plate has wrinkling trend, and value is more big, shows that the wrinkling trend of plate is more serious;

S5, structure are based on the wrinkling forecast model of architectural feature key element: the functional relationship between setting up each architectural feature key element and being wrinkling, assume that between the wrinkling trend of drop stamping beam-like part and architectural feature key element coefficient be simple proportional relation, meet following functional relationship:

${\mathrm{\ϵ}}_{wcj}=k\underset{i=1}{\overset{n}{\Σ}}{n}_i{\mathrm{\α}}_i---\left(4\right),$

Wherein k is proportionality coefficient, ��_iFor architectural feature key element coefficient, represent that corresponding architectural feature key element is to wrinkling contribution;

S6, bring the wrinkling value of stamping parts each in step S3 into formula (4) respectively, obtain the relation between each architectural feature key element coefficient, if ��_i> 0, then it represents that corresponding architectural feature key element has facilitation to wrinkling, weakens this architectural feature key element during product design, if ��_i< 0, then it represents that corresponding architectural feature key element to wrinkling have slow down effect, strengthen this architectural feature key element during product design, thus controlling the generation of wrinkle.

By technique scheme, in step S1, described analysis sample is beam-like part or thin wall component.

By technique scheme, in step S1, described analysis sample is 4 beam-like parts, respectively U-shaped part, S ellbeam, flanged (FLGD) automobile front longitudinal beam inner panel and automobile B-pillar inner plate.

By technique scheme, in step S2, all architectural feature key elements include straight wall, curved surface sidewall, straight end face, bent end face and boss, are respectively labeled as 1,2,3,4,5.

By technique scheme, described stamping parts is cold-stamped part, temperature stamping parts or heat-punch member.

The beneficial effect comprise that: the present invention is by selecting multiple stamping parts with similar structural characteristics as analyzing sample, and the similar structural characteristics of each stamping parts is carried out decomposition obtain each architectural feature key element, the architectural feature key element that each stamping parts comprises is made to have certain intercrossing, every stamping parts with this architectural feature key element all can as prediction object, expand the scope of applicable object so that this method has adaptability widely; Then pass through and set up FEM (finite element) model simulation and obtain the wrinkling value of each stamping parts, the wrinkling forecast model based on each architectural feature key element is set up further according to wrinkling criterion, each architectural feature key element is obtained on wrinkling impact by wrinkling value and wrinkling forecast model analysis, such that it is able to strengthen in the stamping parts design phase or weaken certain architectural feature key element, reach the wrinkling purpose carrying out anticipation to stamping parts in the design phase. The present invention can directly assess, according to wrinkling forecast model, the risk that stamping parts is wrinkling, optimizes stamping parts structural design, reduces die trial number of times, thus reducing design cycle and cost, has significant economy.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the invention will be further described, in accompanying drawing:

Fig. 1 is the structural representation of 4 beam-like parts in the embodiment of the present invention;

Fig. 2 is the punching press FEM (finite element) model schematic diagram of automobile B-pillar inner plate in present inventor's embodiment;

Fig. 3 is the wrinkling analog result figure of 4 beam-like parts in the embodiment of the present invention;

Fig. 4 is the coordinate schematic diagram of 5 architectural feature key element coefficients in the embodiment of the present invention.

In figure: the flanged (FLGD) automobile front longitudinal beam inner panel of 1-U shape part, 2-S ellbeam, 3-, 4-automobile B-pillar inner plate, 5-punch, 6-die, 7-automobile B-pillar inner plate blank.

Detailed description of the invention

In order to make the purpose of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated. Should be appreciated that specific embodiment described herein is only in order to explain the present invention, is not intended to limit the present invention.

Prediction that a kind of stamping parts is wrinkling and control method, comprise the following steps:

S1, choose the multiple stamping parts with similar structural characteristics as analyzing sample;

S2, forming mode due to all stamping parts are all draw formings, so the shape according to similar structural characteristics is classified, the similar structural characteristics of each stamping parts is decomposed, obtain constituting the architectural feature key element 1 of each stamping parts similar structural characteristics, 2,3 ..., n, and the quantity n of each architectural feature key element_i, i=(1,2,3 ..., n), the architectural feature key element that each stamping parts comprises has certain intercrossing, all architectural feature key elements of induction-arrangement;

S3, set up the punching press FEM (finite element) model of each stamping parts, simulate the forming process of each stamping parts, obtain the wrinkling value of each stamping parts;

S4, set up wrinkling criterion: the stress-strain relation of each stamping parts is

$\left.\begin{array}{c}{\mathrm{\&epsiv;}}_1=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}\left({\mathrm{\&sigma;}}_1-\frac{R}{1+R}{\mathrm{\&sigma;}}_2\right)\\ {\mathrm{\&epsiv;}}_2=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}\left({\mathrm{\&sigma;}}_2-\frac{R}{1+R}{\mathrm{\&sigma;}}_1\right)\\ {\mathrm{\&epsiv;}}_t=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}\frac{{\mathrm{\&sigma;}}_1+{\mathrm{\&sigma;}}_2}{1+R}\end{array}\right\}---\left(1\right),$

Wherein, ��₁It is plane principal strain, ��₂It is plane time strain, ��_tBeing perpendicular to the principal strain in direction, plate face, R is average the coefficient of normal anisortopy, ��_iIt is equivalent strain, ��_iIt it is equivalent stress;

Compressive stress owing to being parallel to plate face causes wrinkling, therefore the generation of wrinkle and secondary stress ��₂Relevant, obtain according to formula (1)

${\mathrm{\&sigma;}}_2=\mathrm{\&lambda;}({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1)---\left(2\right),$

Wherein,Work as ��₂When=0, plate is in unidirectional tension state, is occur with the form of uniaxial tension line in forming limit diagram, using this uniaxial tension line as substantially wrinkling criterion, it is considered to the loading history impact on wrinkling impact and geometry size, obtains wrinkling criterion

${\mathrm{\&epsiv;}}_{wc}=\mathrm{\&rho;}\{max\&lsqb;-({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1),0\&rsqb;-min\&lsqb;-({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1),0\&rsqb;\}---\left(3\right),$

Wherein, �� is the coefficient relevant with curvature, ��_wc>=0, work as ��_wcWhen=0, plate, without wrinkling, works as ��_wcDuring > 0, plate has wrinkling trend, and value is more big, shows that the wrinkling trend of plate is more serious;

S5, structure are based on the wrinkling forecast model of architectural feature key element: the functional relationship between setting up each architectural feature key element and being wrinkling, assume that between the wrinkling trend of drop stamping beam-like part and architectural feature key element coefficient be simple proportional relation, meet following functional relationship:

${\mathrm{\&epsiv;}}_{wcj}=k\underset{i=1}{\overset{n}{\&Sigma;}}{n}_i{\mathrm{\&alpha;}}_i---\left(4\right),$

Wherein k is proportionality coefficient, ��_iFor architectural feature key element coefficient, represent that corresponding architectural feature key element is to wrinkling contribution;

S6, bring the wrinkling value of stamping parts each in step S3 into formula (4) respectively, obtain the relation between each architectural feature key element coefficient, if ��_i> 0, then it represents that corresponding architectural feature key element has facilitation to wrinkling, weakens this architectural feature key element during product design, if ��_i< 0, then it represents that corresponding architectural feature key element to wrinkling have slow down effect, strengthen this architectural feature key element during product design, thus controlling the generation of wrinkle.

Stamping parts in the present invention can be cold-stamped part, temperature stamping parts and heat-punch member, and the present invention to having the beam-like part of similar structural characteristics or the wrinkling of thin wall component is predicted and controls, can have adaptability widely. Below for the beam-like part of drop stamping, the present invention comprises the following steps:

S1, as shown in Figure 1, to be chosen in architectural feature similar but has 4 beam-like parts of different as analyzing sample, this 4 stamping parts respectively U-shaped part 1, S ellbeam 2, flanged (FLGD) automobile front longitudinal beam inner panel 3 and automobile B-pillar inner plate 4, its diversity in architectural feature is presented as and is shaped like but complexity is different;

S2, definition beam-like part architectural feature key element: the similar structural characteristics of each stamping parts is decomposed, obtains constituting the architectural feature key element 1,2,3,4,5 of each stamping parts similar structural characteristics and the quantity n of each architectural feature key element_i, i=(1, 2, 3, 4, 5), refer to table 1, respectively U-shaped part 1 has 2 straight wall and 1 straight end face, S ellbeam 2 has 2 curved surface sidewalls and 1 straight end face, flanged (FLGD) automobile front longitudinal beam inner panel 3 has 2 straight wall and 1 bent end face, automobile B-pillar inner plate 4 has 2 straight wall, 2 curved surface sidewalls, 1 bent end face and 3 boss, the architectural feature key element that each stamping parts comprises has certain intercrossing, namely at least two stamping parts comprises common architectural feature key element, screen and conclude all architectural feature key elements, by straight wall, curved surface sidewall, straight end face, bent end face and boss are defined as the architectural feature key element of beam-like part, it is respectively labeled as 1, 2, 3, 4, 5, sidewall and end face right and wrong is determine by observing cross section that part cuts open along xoy face and xoz face respectively,

The distribution in drop stamping beam-like part sample of the table 1 each architectural feature key element

Architectural feature key element	U-shaped part	S ellbeam	Flanged (FLGD) automobile front longitudinal beam inner panel	Automobile B-pillar inner plate
					Straight wall (n1)	2	0	2	2
Curved surface sidewall (n2)	0	2	0	2
					Straight end face (n3)	1	1	0	0
Bent end face (n4)	0	0	1	1
					Boss (n5)	0	0	0	3

S3, set up the drop stamping FEM (finite element) model of each stamping parts by Finite Element Method, as shown in Figure 2, for automobile B-pillar inner plate, its FEM (finite element) model includes the blank 7 of punch 5, die 6 and the automobile B-pillar inner plate that is arranged between punch 5 and die 6, as shown in Figure 3, simulate the forming process of each stamping parts, obtain the wrinkling value of each stamping parts, as shown in table 2;

The wrinkling value of each stamping parts of table 2

Part type	��wcj(%)	ni��i
			U-shaped part	0.43	2��1+��3
S ellbeam	2.42	2��2+��3
			Automobile front longitudinal beam inner panel	6.46	2��1+��4
Automobile B-pillar inner plate	5.50	2��1+2��2+��4+3��5

S4, set up wrinkling criterion: generation principle according to wrinkle and influence factor in the present embodiment, utilize the wrinkling trend (wrinkling risk) of wrinkling criteria evaluation drop stamping part sample, simple when loading the stress-strain relation of thick anisotropy plate be

$\left.\begin{array}{c}{\mathrm{\&epsiv;}}_1=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}\left({\mathrm{\&sigma;}}_1-\frac{R}{1+R}{\mathrm{\&sigma;}}_2\right)\\ {\mathrm{\&epsiv;}}_2=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}\left({\mathrm{\&sigma;}}_2-\frac{R}{1+R}{\mathrm{\&sigma;}}_1\right)\\ {\mathrm{\&epsiv;}}_t=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}\frac{{\mathrm{\&sigma;}}_1+{\mathrm{\&sigma;}}_2}{1+R}\end{array}\right\}---\left(1\right),$

Wherein, ��₁It is plane principal strain, ��₂It is plane time strain (being called for short time strain), ��_tBeing perpendicular to the principal strain in direction, plate face, R is average the coefficient of normal anisortopy, ��_iIt is equivalent strain, ��_iIt it is equivalent stress;

Compressive stress owing to being parallel to plate face causes wrinkling, therefore the generation of wrinkle and secondary stress ��₂Relevant, obtain according to formula (1)

${\mathrm{\&sigma;}}_2=\mathrm{\&lambda;}({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1)---\left(2\right),$

Wherein,Work as ��₂When=0, plate is in unidirectional tension state, forming limit diagram is occur with the form of uniaxial tension line, using this uniaxial tension line as substantially wrinkling criterion, consider the loading history impact (example: curved surface area material usually thickens rather than wrinkling) on wrinkling impact and geometry size, obtain wrinkling criterion

${\mathrm{\&epsiv;}}_{wc}=\mathrm{\&rho;}\{max\&lsqb;-({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1),0\&rsqb;-min\&lsqb;-({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1),0\&rsqb;\}---\left(3\right),$

Wherein, �� is the coefficient relevant with curvature, ��_wc>=0, work as ��_wcWhen=0, plate, without wrinkling, works as ��_wcDuring > 0, plate has wrinkling trend, and value is more big, shows that the wrinkling trend of plate is more serious;

S5, structure are based on the wrinkling forecast model of architectural feature key element: the functional relationship between setting up each architectural feature key element and being wrinkling, wrinkling forecast model about architectural feature key element, both can be set up by analytic method, the technology such as artificial neural network can also be passed through obtain, assume that between the wrinkling trend of drop stamping beam-like part and architectural feature key element coefficient be simple proportional relation, meet following functional relationship:

${\mathrm{\&epsiv;}}_{wcj}=k\underset{i=1}{\overset{n}{\&Sigma;}}{n}_i{\mathrm{\&alpha;}}_i---\left(4\right),$

Wherein k is proportionality coefficient, ��_iFor architectural feature key element coefficient, represent that corresponding architectural feature key element is to wrinkling contribution;

S6, bring the wrinkling value of stamping parts each in step S3 into formula (4) respectively, obtain the relation between each architectural feature key element coefficient,

$\left.\begin{array}{c}{\mathrm{\&alpha;}}_2=\frac{0.995\%+{\mathrm{\&alpha;}}_{1}k}{k}\\ {\mathrm{\&alpha;}}_3=\frac{0.43\%-2{\mathrm{\&alpha;}}_{1}k}{k}\\ {\mathrm{\&alpha;}}_4=\frac{6.46\%-2{\mathrm{\&alpha;}}_{1}k}{k}\\ {\mathrm{\&alpha;}}_5=\frac{-2.95\%-2{\mathrm{\&alpha;}}_{1}k}{3k}\end{array}\right\}---\left(5\right),$

Relational expression (5) is expressed in rectangular coordinate system with the form of slope, as shown in Figure 4, it is possible to obtain, ��₂>��₁> 0, ��₄> 0, ��₃< 0, ��₅< 0, if ��_i> 0, then it represents that corresponding architectural feature key element has facilitation to wrinkling, weakens this architectural feature key element during product design, if ��_i< 0, then it represents that corresponding architectural feature key element to wrinkling have slow down effect, strengthen this architectural feature key element during product design.

From relational expression (5) and Fig. 4: (1) sidewall has facilitation to wrinkling, and wrinkling impact ratio is faced directly the big of sidewall by curved surface sidewall, for this, wrinkling for preventing, sidewall particularly curved surface sidewall is focused on during product design, if cannot be avoided curved surface sidewall, then can suitably increase boss structure, or on die face, suitably increase bead;

(2) to affect amplitude relatively larger on wrinkling for end face, but model of action is different, straight end face is unfavorable for the generation of wrinkle, bent end face can cause wrinkling, for this, wrinkling for preventing, bent end face is suitably reduced during product design, if cannot be avoided bent end face, then plate can be carried out predeformation so that plate can contact in stamping process with die face simultaneously;

(3) boss to wrinkling have significantly slow down effect, this is owing to boss has suction effect, thus can eliminate some wrinkles, for this, wrinkling for preventing, during product design increase boss.

In the present invention architectural feature key element and wrinkling between functional relationship can reflect that each architectural feature key element is on wrinkling impact intuitively. The present invention different choice according to punching parts sample, architectural feature key element and the functional relationship between wrinkling also change therewith, and therefore, this method has certain elasticity.

It should be appreciated that for those of ordinary skills, it is possible to improved according to the above description or converted, and all these are improved and convert the protection domain that all should belong to claims of the present invention.

Claims (5)

1. a stamping parts is wrinkling prediction and control method, it is characterised in that comprise the following steps:

S1, choose the multiple stamping parts with similar structural characteristics as analyzing sample;

S2, shape according to similar structural characteristics, decompose the similar structural characteristics of each stamping parts, obtain constituting the architectural feature key element 1 of each stamping parts similar structural characteristics, 2,3 ..., n, and the quantity n of each architectural feature key element_i, i=(1,2,3 ..., n), the architectural feature key element that each stamping parts comprises has certain intercrossing, all architectural feature key elements of induction-arrangement;

S3, set up the punching press FEM (finite element) model of each stamping parts, simulate the forming process of each stamping parts, obtain the wrinkling value of each stamping parts;

S4, set up wrinkling criterion: the stress-strain relation of each stamping parts is

$\left.\begin{array}{c}{\mathrm{\&epsiv;}}_1=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}({\mathrm{\&sigma;}}_1-\frac{R}{1+R}{\mathrm{\&sigma;}}_2)\\ {\mathrm{\&epsiv;}}_2=\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}({\mathrm{\&sigma;}}_2-\frac{R}{1+R}{\mathrm{\&sigma;}}_1)\\ {\mathrm{\&epsiv;}}_t=-\frac{{\mathrm{\&epsiv;}}_i}{{\mathrm{\&sigma;}}_i}\frac{{\mathrm{\&sigma;}}_1+{\mathrm{\&sigma;}}_2}{1+R}\end{array}\right\}---\left(1\right),$

Wherein, ��₁It is plane principal strain, ��₂It is plane time strain, ��_tBeing perpendicular to the principal strain in direction, plate face, R is average the coefficient of normal anisortopy, ��_iIt is equivalent strain, ��_iIt it is equivalent stress;

Compressive stress owing to being parallel to plate face causes wrinkling, therefore the generation of wrinkle and secondary stress ��₂Relevant, obtain according to formula (1)

${\mathrm{\&sigma;}}_2=\mathrm{\&lambda;}({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1)---\left(2\right),$

Wherein,Work as ��₂When=0, plate is in unidirectional tension state, is occur with the form of uniaxial tension line in forming limit diagram, using this uniaxial tension line as substantially wrinkling criterion, it is considered to the loading history impact on wrinkling impact and geometry size, obtains wrinkling criterion

${\mathrm{\&epsiv;}}_{wc}=\mathrm{\&rho;}\{max\&lsqb;-({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1),0\&rsqb;-min\&lsqb;-({\mathrm{\&epsiv;}}_2+\frac{R}{R+1}{\mathrm{\&epsiv;}}_1),0\&rsqb;\}---\left(3\right),$

Wherein, �� is the coefficient relevant with curvature, ��_wc>=0, work as ��_wcWhen=0, plate, without wrinkling, works as ��_wcDuring > 0, plate has wrinkling trend, and value is more big, shows that the wrinkling trend of plate is more serious;

S5, structure are based on the wrinkling forecast model of architectural feature key element: the functional relationship between setting up each architectural feature key element and being wrinkling, assume that between the wrinkling trend of drop stamping beam-like part and architectural feature key element coefficient be simple proportional relation, meet following functional relationship:

${\mathrm{\&epsiv;}}_{wcj}=k\underset{i=1}{\overset{n}{\&Sigma;}}{n}_i{\mathrm{\&alpha;}}_i---\left(4\right),$

Wherein k is proportionality coefficient, ��_iFor architectural feature key element coefficient, represent that corresponding architectural feature key element is to wrinkling contribution;

S6, bring the wrinkling value of stamping parts each in step S3 into formula (4) respectively, obtain the relation between each architectural feature key element coefficient, if ��_i> 0, then it represents that corresponding architectural feature key element has facilitation to wrinkling, weakens this architectural feature key element during product design, if ��_i< 0, then it represents that corresponding architectural feature key element to wrinkling have slow down effect, strengthen this architectural feature key element during product design, thus controlling the generation of wrinkle.

2. method according to claim 1, it is characterised in that in step S1, described analysis sample is beam-like part or thin wall component.

3. method according to claim 1, it is characterised in that in step S1, described analysis sample is 4 beam-like parts, respectively U-shaped part, S ellbeam, flanged (FLGD) automobile front longitudinal beam inner panel and automobile B-pillar inner plate.

4. method according to claim 3, it is characterised in that in step S2, all architectural feature key elements include straight wall, curved surface sidewall, straight end face, bent end face and boss, are respectively labeled as 1,2,3,4,5.

5. method according to claim 1, it is characterised in that described stamping parts is cold-stamped part, temperature stamping parts or heat-punch member.