CN104133930A - Damage process simulation method of composite material laminate plate - Google Patents

Abstract

The invention belongs to the field of airplane design, and relates to a damage process simulation method of a composite material laminate plate under low-velocity impact. The damage process simulation method of the composite material laminate plate is characterized in that a numerical value simulation analysis method of the low-velocity impact damage of the composite material laminate plate by adopting an ABAQUS user subprogram is provided, and the numerical value simulation of the damage starting, accumulation to damage processes of a composite material structure can be carried out. The invention has the beneficial effects that a damage process during the bearing of the laminate plate can be clearly known, and a technical means is provided for effectively analyzing the structural damage tolerance of the composite material laminate plate in an airplane structure.

Description

A kind of composite laminated plate damage process analogy method

Technical field

The invention belongs to airplane design field, relate to a kind of Laminated Composites Under Low Velocity Impact Loading damage process analogy method.

Background technology

Low-velocity impact damage is on there being larger impact in the intensity of compound substance, rigidity and serviceable life.For the structural damage tolerance limit of composite-material laminates in effective analysis of aircraft structure, the damage and failure course while must be well understood that laminate carrying, is therefore necessary to carry out the numerical simulation study of composite structure damage process.

Laminate Strength of Composites computational analysis generally can adopt general finite element software ABAQUS to carry out, but the analysis module carrying by ABAQUS software, can only obtain the strain and stress distribution after composite laminated plate is hit, after cannot being hit for composite-material laminates, damage initial, be accumulate to destructive process and simulate.

Summary of the invention

The object of the invention is: a kind of Numerical Simulation Analysis method that Composite Laminated Plate under Low-Velocity Impact damage of the ABAQUS of utilization user subroutine is provided, by ABAQUS software users subroutine interface, can carry out the numerical simulation that composite structure damage is initial, be accumulate to destructive process.

Technical scheme of the present invention is: a kind of damage process analogy method of the Laminated Composites Under Low Velocity Impact Loading based on ABAQUS software users subroutine, it is characterized in that, and comprise the steps:

The first, set up the finite element model of composite laminated plate

The finite element block mold of setting up composite laminated plate in ABAQUS/CAE, comprises finite element grid, material, boundary condition, and quality of exotic, impact velocity etc.

The second, according to the different damage types of composite-material laminates, damage criterion is proposed

Galss fiber reinforced resin based composites one-way slabs is subject to the failure mode under low velocity impact to have three kinds: fibre breakage, MATRIX CRACKING and matrix squeeze crack.Because compound substance single-ply plate is from producing damage until destruction all shows as elasticity, therefore can not consider the impact of plastic yield.According to the difference of damage mode, provide following damage criterion:

A) fibre breakage

For the fibre breakage shown in Fig. 2, its damage criterion is:

${\left(\frac{{\mathrm{\σ}}_{11}}{X_T}\right)}^2+\left(\frac{{\mathrm{\σ}}_{12}^2+{\mathrm{\σ}}_{13}^2}{S_f^2}\right)\≥1$

B) MATRIX CRACKING

For the MATRIX CRACKING shown in Fig. 3, its damage criterion is:

${\left(\frac{{\mathrm{\σ}}_{22}}{Y_T}\right)}^2+{\left(\frac{{\mathrm{\σ}}_{12}}{S_{12}}\right)}^2+{\left(\frac{{\mathrm{\σ}}_{23}}{S_{m23}}\right)}^2\≥1,{\mathrm{\σ}}_{22}\≥0$

C) matrix squeeze crack

For the matrix squeeze crack shown in Fig. 4, its damage criterion is:

$\frac{1}{4}{\left(\frac{-{\mathrm{\&sigma;}}_{22}}{S_{12}}\right)}^2+\frac{{Y_c}^2{\mathrm{\&sigma;}}_{22}}{4S_{12}^2{Y}_c}-\frac{{\mathrm{\&sigma;}}_{22}}{Y_c}+{\left(\frac{{\mathrm{\&sigma;}}_{12}}{S_{12}}\right)}^2\&GreaterEqual;1,{\mathrm{\&sigma;}}_{22}<0$

D) delamination criterion

Layering is composite laminated plate main damage type while being subject to low velocity impact, in ABAQUS, utilizes COHESIVE unit to carry out bonded areas between simulation layer.In composite laminated plate, lamina can be thought transverse isotropy material, and the cracking model corresponding to two shear stress components in layers cementing region is respectively II type and III type crackle, and has G _iIC=G _iIIC, for this feature of composite laminated plate, for the COHESIVE unit that is positioned at interlayer, adopt following cracking criterion:

$G^C=G_n^C+(G_s^C-G_n^C){\left(\frac{G_S}{G_T}\right)}^{\mathrm{\&eta;}}$

G wherein _s=G _s+ G _t, G _t=G _n+ G _s.When given after η, the strain energy release rate G of material _cbe exactly G _s/ G _tdefinite function.

The 3rd, the method for employing reduction element stiffness matrix, the element stress that satisfied damage is sentenced upgrades

In ABAQUS, arrange while calculating step step, whole step computation process should be divided into a plurality of increment, utilize user's subroutine function UMAT of ABAQUS to upgrade the unit result of calculation stress of each increment, and by damage criterion differentiate be hit after unit whether sustain damage, in composite laminated plate, the stress level of unit has met after damage criterion, the corresponding components of stress in unit are made as to 0, and representative unit loses load-bearing capacity in this direction; When damage condition does not meet, impairment parameter does not equal 1.Identical with actual conditions, once impairment parameter equals after 0, its value is just 0 always, represents that unit has lost load-bearing capacity, and concrete calculation procedure is as follows:

First by subroutine SDVINI definition original state variable, then utilize subroutine UMAT to read in the initial stiffness matrix of each unit, according to damage criterion judging unit, whether there is damage, if there is not damage, continue to use initial cell stiffness matrix to carry out stress renewal; If there is damage, element stiffness matrix is carried out to reduction, use the element stiffness matrix of degenerating to upgrade stress.

Concrete element stress update scheme is as table 1.Wherein, D _f, D _mand D _mcthe impairment parameter that represents respectively fibre breakage, MATRIX CRACKING and matrix squeeze crack, when meeting damage condition, they equal 1, and the corresponding components of stress in unit are just set to 0; When damage condition does not meet, impairment parameter does not equal 0.Identical with actual conditions, once impairment parameter equals after 1, its value is just 1 always, represents that unit has lost load-bearing capacity.

Table 1 stress update scheme

The 4th, submit to ABAQUS/standard to calculate calculation document and user's subroutine, obtain result of calculation.

Advantage of the present invention is:

1) utilize ABAQUS user's subroutine, can carry out real-time update to the stress of each unit of composite laminated plate, the variation that in the process that analog composite material layer plywood is hit accurately, stress distribution occurs, for the unit that meets damage criterion, by user's subroutine, allow it lose load-bearing capacity, represent that this place produces damage; Along with the increase of load, more multiple-unit meets damage criterion, and increasing unit loses load-bearing capacity, has represented the progressively expansion of damage;

2) because composite failure pattern is various, adopt ABAQUS user's subroutine to provide the damage criterion under different failure modes according to user's actual requirement, make more approaching to reality situation of simulation analysis.

Accompanying drawing explanation

Fig. 1 is embodiment of the present invention composite laminated plate finite element model schematic diagram.

Fig. 2 is embodiment of the present invention composite-material laminates fibre breakage failure mode schematic diagram.

Fig. 3 is embodiment of the present invention composite-material laminates MATRIX CRACKING failure mode schematic diagram.

Fig. 4 is embodiment of the present invention composite layer board substrate squeeze crack failure mode schematic diagram.

Degree of impairment schematic diagram when Fig. 5 is embodiment of the present invention composite-material laminates t=0.1ms.

Degree of impairment schematic diagram when Fig. 6 is embodiment of the present invention composite-material laminates t=0.2ms.

Degree of impairment schematic diagram when Fig. 7 is embodiment of the present invention composite-material laminates t=0.3ms.

Degree of impairment schematic diagram when Fig. 8 is embodiment of the present invention composite-material laminates t=0.4ms.

Degree of impairment schematic diagram when Fig. 9 is embodiment of the present invention composite-material laminates t=0.6ms.

Figure 10 is that the embodiment of the present invention is impacted the situation schematic diagram that finishes the layering of rear laminate through-thickness.

Figure 11 is the thickness direction interlayer layering situation schematic diagram that embodiment of the present invention test obtains.

Embodiment

Below by specific embodiment, also the present invention is described in further detail by reference to the accompanying drawings.

In ABAQUS/CAE, set up the finite element block mold of glass/epoxy composite laminated plate, the layering type of laminate is [0/90] staggered laying, and thickness in monolayer is 1.8 * 10 ^-4m, totally 10 layers, laminate length of side d=0.16m, density p=1678kg/m ³, material property parameter is in Table 2.The boundary condition of computation model is simple supported edge, finite element grid as shown in Figure 1, its la m unit adopts C3D8R unit, it is Three-Dimensional 8-node Reduced Integral solid element, with a quality m=0.26kg, the rigid body bead of impact velocity v=7.08m/s is simulated laminate and is subject to foreign matter impact, because impact process is very short, and the interaction force between bead and laminate is much larger than gravity in the meantime, therefore the effect of gravity is not considered in all calculating.

Table 2 composite-material laminates material property parameter

Utilize ABAQUS/standard to calculate the process that simulation bead impacts laminate, the degree of impairment of unit after utilizing user's subroutine function SDVINI and UMAT differentiation to be hit, in composite laminated plate, the stress level of unit has met after damage criterion, and the corresponding components of stress in unit can be considered as 0.According to this principle, can upgrade the stress of unit after damage and failure.

The COHESIVE unit that black region representative in Fig. 3 destroys, i.e. the region of interlayer layering.T=0.6ms in Fig. 3, is the moment of impact process laminate displacement maximum, and in figure, deformation comparison is acutely because fibre breakage causes in laminate.Fig. 4 is the situation that impact that finite element analogy obtains finishes the layering of rear laminate thickness direction, near region below shock point does not have layering owing to being subject to the extruding of bead, the full-size of interlayer layering is 20mm, the full-size of testing as shown in Figure 5 interlayer layering is 19mm, and simulation coincide better with the result that test obtains.

The method has been carried out the exploitation of user's subroutine on inventing on ABAQUS basis of software, simulated after composite-material laminates is hit, damage initial, be accumulate to destructive process, computational accuracy is reliable, and thoroughly having solved direct use ABAQUS software can not carry out the deficiency of simulation analysis to the composite laminated plate damage process that is hit.

Claims (1)

1. a composite laminated plate damage process analogy method, is characterized in that, it is characterized in that, comprises the steps:

The first, set up the finite element model of composite laminated plate

The finite element block mold of setting up composite laminated plate in ABAQUS/CAE, comprises finite element grid, material, boundary condition, and the quality of exotic and impact velocity;

The second, according to the different damage types of composite-material laminates, damage criterion is proposed

Galss fiber reinforced resin based composites one-way slabs is subject to the failure mode under low velocity impact to have three kinds: fibre breakage, MATRIX CRACKING and matrix squeeze crack; According to the difference of damage mode, provide following damage criterion:

A) fibre breakage

Fibre breakage damage criterion is:

${\left(\frac{{\mathrm{\&sigma;}}_{11}}{X_T}\right)}^2+\left(\frac{{\mathrm{\&sigma;}}_{12}^2+{\mathrm{\&sigma;}}_{13}^2}{S_f^2}\right)\&GreaterEqual;1$

B) MATRIX CRACKING

MATRIX CRACKING damage criterion is:

${\left(\frac{{\mathrm{\&sigma;}}_{22}}{Y_T}\right)}^2+{\left(\frac{{\mathrm{\&sigma;}}_{12}}{S_{12}}\right)}^2+{\left(\frac{{\mathrm{\&sigma;}}_{23}}{S_{m23}}\right)}^2\&GreaterEqual;1,{\mathrm{\&sigma;}}_{22}\&GreaterEqual;0$

C) matrix squeeze crack

Matrix squeeze crack damage criterion is:

$\frac{1}{4}{\left(\frac{-{\mathrm{\&sigma;}}_{22}}{S_{12}}\right)}^2+\frac{{Y_c}^2{\mathrm{\&sigma;}}_{22}}{4S_{12}^2{Y}_c}-\frac{{\mathrm{\&sigma;}}_{22}}{Y_c}+{\left(\frac{{\mathrm{\&sigma;}}_{12}}{S_{12}}\right)}^2\&GreaterEqual;1,{\mathrm{\&sigma;}}_{22}<0$

D) delamination criterion

For the COHESIVE unit that is positioned at interlayer, adopt following cracking criterion:

$G^C=G_n^C+(G_s^C-G_n^C){\left(\frac{G_S}{G_T}\right)}^{\mathrm{\&eta;}}$

G wherein _s=G _s+ G _t, G _t=G _n+ G _s;

The 3rd, the method for employing reduction element stiffness matrix, the element stress that satisfied damage is sentenced upgrades, and concrete calculation procedure is as follows:

First by subroutine SDVINI definition original state variable, then utilize subroutine UMAT to read in the initial stiffness matrix of each unit, according to damage criterion judging unit, whether there is damage, if there is not damage, continue to use initial cell stiffness matrix to carry out stress renewal; If there is damage, element stiffness matrix is carried out to reduction, use the element stiffness matrix of degenerating to upgrade stress;

Concrete element stress update scheme is as table 1; Wherein, D _f, D _mand D _mcthe impairment parameter that represents respectively fibre breakage, MATRIX CRACKING and matrix squeeze crack, when meeting damage condition, they equal 1, and the corresponding components of stress in unit are just set to 0; When damage condition does not meet, impairment parameter does not equal 0; Identical with actual conditions, once impairment parameter equals after 1, its value is just 1 always, represents that unit has lost load-bearing capacity;

Table 1 stress update scheme

The 4th, submit to ABAQUS/standard to calculate calculation document and user's subroutine, obtain result of calculation.