Abaqus复合材料

1 Copyright 2008 SIMULIA, Inc. 模拟复合材料的真实性能 Abaqus北京代表处 2008年7月 Copyright 2008 SIMILIA, Inc. 概述 复合材料被许多工业领域广泛的使用复合材料被许多工业领域广泛的使用复合材料被许多工业领域广泛的使用复合材料被许多工业领域广泛的使用 航空 卫星 火箭 F1 潜艇 2 Copyright 2008 SIMILIA, Inc. 概述 复合材料的增强形式有很多种复合材料的增强形式有很多种复合材料的增强形式有很多种复合材料的增强形式有很多种： 颗粒增强 随机分布短纤维 单向纤维 平面编织 三维编织 Copyright 2008 SIMILIA, Inc. 概述 复合材料具有很多的优点复合材料具有很多的优点复合材料具有很多的优点复合材料具有很多的优点： 制造工艺简单 比强度高，比刚度大 具有灵活的可设计性 耐腐蚀，对疲劳不敏感 热稳定性、高温性能好 3 Copyright 2008 SIMILIA, Inc. Abaqus中复合材料的建模技术 根据分析目的的不同根据分析目的的不同根据分析目的的不同根据分析目的的不同，复合材料的建模方式有复合材料的建模方式有复合材料的建模方式有复合材料的建模方式有： 分层的壳单元 分层的实体单元 实体壳单元 高级的复合材料建模技术包括高级的复合材料建模技术包括高级的复合材料建模技术包括高级的复合材料建模技术包括： Rebar单元 嵌入单元 Copyright 2008 SIMILIA, Inc. 分层的壳单元 单元单元单元单元 S4, S3R 属性定义属性定义属性定义属性定义 *SHELL SECTION, COMPOSITE 材料定义材料定义材料定义材料定义 *ELASTIC, TYPE=ISOTROPIC, TYPE=LAMINA Shell MeshShell MeshShell MeshShell Mesh 4 Copyright 2008 SIMILIA, Inc. 分层的实体单元 可以在六面体单元的任意方向定义任意数量的分层 分层的实体单元计算横向剪切应力的精度不如厚壳单元 单元单元单元单元 C3D8I, C3D6 属性定义属性定义属性定义属性定义 *SOLID SECTION, COMPOSITE 材料定义材料定义材料定义材料定义 *ELASTIC, TYPE=ISOTROPIC, TYPE=ORTHOTROPIC, TYPE=ANISOTROPIC Solid MeshSolid MeshSolid MeshSolid Mesh Copyright 2008 SIMILIA, Inc. 实体壳单元 实体壳单元是三维应力/位移单元，它的响应同壳类似，但是具有实体的拓扑 单元单元单元单元 SC6R，SC8R 属性定义属性定义属性定义属性定义 *SHELL SECTION, COMPOSITE，STACKING DIRECTION=1|2|3|orientation 材料定义材料定义材料定义材料定义 *ELASTIC, TYPE=ISOTROPIC, TYPE=LAMINA 5 Copyright 2008 SIMILIA, Inc. 实体壳单元 优势优势优势优势： 实体壳单元可以： 厚壳和薄壳的应用 线形和非线性行为（大变形和弹-塑性材料响应） 厚度的锥形变化/厚度的逐渐减少 利用三维单元划分网格的几何体得到的单元 考虑双面接触 可以更加精确的模拟复合材料层合结构厚度方向的响应 单元可以具有较高的纵横比（面内尺寸和厚度的比值） Copyright 2008 SIMILIA, Inc. 高级的复合材料建模技术Rebar单元 利用利用利用利用Rebar模拟复合材料模拟复合材料模拟复合材料模拟复合材料 钢筋混凝土、橡胶轮胎等 假设母体和增强结构是完全绑定的 *REBAR LAYER 用于模拟壳、薄膜和表面单元中单轴增强结构 6 Copyright 2008 SIMILIA, Inc. Rebar单元 使用方法使用方法使用方法使用方法： *SHELL SECTION, ELSET=. *REBAR LAYER, ORIENTATION=ORI1 name, a, s, f, mat, alpha, 1 *SHELL SECTION, ELSET=. *REBAR LAYER, ORIENTATION=ORI1 name, a, s, f, mat, alpha, 1 asalphafmatname Copyright 2008 SIMILIA, Inc. 嵌入单元 Rebar加强的膜单元和表面单元可以以任意方式嵌入到实体单元中来模拟 复合材料 嵌入的膜单元 rebar 实体单元 7 Copyright 2008 SIMILIA, Inc. Abaqus复合材料主要功能 Abaqus/CAE复合材料的定义以及后处理功能复合材料的定义以及后处理功能复合材料的定义以及后处理功能复合材料的定义以及后处理功能 CATIA CPD的接口的接口的接口的接口 高级复合材料模拟技术高级复合材料模拟技术高级复合材料模拟技术高级复合材料模拟技术 Copyright 2008 SIMILIA, Inc. 复合材料定义的界面Composite Layup 1 2 3 8 Copyright 2008 SIMILIA, Inc. 复合材料定义的界面Composite Layup Copyright 2008 SIMILIA, Inc. 复合材料的后处理功能 9 Copyright 2008 SIMILIA, Inc. 复合材料的后处理功能 可以显示复合材料厚度方向上变量可以显示复合材料厚度方向上变量可以显示复合材料厚度方向上变量可以显示复合材料厚度方向上变量 的变化曲线的变化曲线的变化曲线的变化曲线 Copyright 2008 SIMILIA, Inc. CATIA CPD接口 Simulayt可以作为可以作为可以作为可以作为Abaqus/CAE的中模块的中模块的中模块的中模块，将将将将CATIA CPD中设计的复合中设计的复合中设计的复合中设计的复合 材料模型以及铺层导入材料模型以及铺层导入材料模型以及铺层导入材料模型以及铺层导入 10 Copyright 2008 SIMILIA, Inc. Advanced Simulation Capabilities Manufacturing and Draping Analysis Ballistic impact on unidirectional composite Barely Visible Impact Damage (BVID) Woven fabric composite beam crush Composite plate post-buckling behavior Skin-stringer debonding using VCCT Delamination using cohesive elements Z-pinned composite failure Copyright 2008 SIMILIA, Inc. Debonding using VCCT: Analysis of Composite Skin-Stringer Bonded Joint VCCT can be applied to determine the global strength and failure mode for typical aerospace composite structures like this skin/stringer panel Courtesy Boeing 11 Copyright 2008 SIMILIA, Inc. Abaqus VCCT Capability Developed by Boeing for Fracture Analysis of Composite Aerospace Structures The VCCT-for-Abaqus technology was developed by Boeing Commercial Aircraft Group as part of the Composite Affordability Initiative (CAI) Abaqus was selected by Boeing to commercialize this capability Copyright 2008 SIMILIA, Inc. Virtual Crack Closure Technique (VCCT) VCCT Has been used manually in the aerospace industry for many years Based on Linear Elastic Fracture Mechanics (LEFM) concepts Based on computing the energy release rates for normal and shear crack-tip deformation modes Compare energy release rates to interlaminar fracture toughness Fracture mechanics interface elements control growth of delamination into new material Interface Elements located along plane of delamination Interface elements located along plane of delamination Fracture mechanics interface elements control growth of delamination into new material 12 Copyright 2008 SIMILIA, Inc. VCCT-for-Abaqus Usage and Keywords Abaqus approach is surface based Extension of DEBOND Automatic (inherent) modeling of post failure contact *CONTACT PAIR, INTERACTION=FRACTURE, ADJUST=Nsetbond Slave-Slave surface name Master-Master surface name *SURFACE INTERACTION, NAME=FRACTURE, UCRACK, DEPVAR=12, PROPERTIES=16 , G_IC,G_IIC,G_IIIC,mixType,m,n,o w, Delamination plane paved with surface based contact pair Copyright 2008 SIMILIA, Inc. Surface Interaction Properties Define Fracture Mechanics Properties (given on data line) G_IC G_IIC= Fracture toughness, modes I, II, and III G_IIIC = 1 for B-K (2D shown): mixType = 2 for Power law: eta= Coefficient for B-K law m, n, o= Exponents for mode mixity formula w= Out-of-plane width for 2D analysis o IIIC III n IIC II m IC I G G G G G G + + () m III IIC ICIICIC GG G GGG + + 13 Copyright 2008 SIMILIA, Inc. Skin-Stringer FEA Model Displacement imposed at corner nodes Contact surfaces defined for region of fracture Copyright 2008 SIMILIA, Inc. To Simulate the Test, Center Region of Nodes Are Initially Debonded Initially bonded nodes Initially debonded nodes Crack tip 14 Copyright 2008 SIMILIA, Inc. Animation of Deformed Shape from Analysis Copyright 2008 SIMILIA, Inc. Animation of Debond Propagation 15 Copyright 2008 SIMILIA, Inc. Fracture Analysis Results Force level 1 Force level 2 Force level 3 Deflected shape VCCT Fracture Copyright 2008 SIMILIA, Inc. Crack Growth Predictions Correlate Well With Test Observations Panel Experimental Failure Initiation Load (KN) Abaqus VCCT Predicted Failure Initiation Load (KN) Panel #1146 Panel #2154116 (initiation) Panel #3175148 (growth) *NOTE: Experimental failure load based on first sound of cracking Test results courtesy of Cooperative Research Centre for Advanced Composite Structures (CRC-ACS) 16 Copyright 2008 SIMILIA, Inc. Test Panel Measurement Locations LVDT #1 STIFFENER SIDE PARALLEL TO EDGE PARALLEL TO EDGE LSG#15 LSG#13 274 RSG#7 & #10 150 180 LOAD DIRECTION 70 155180 130 150 RSG#9 & #12 RSG#8 & #11 LSG#14 LSG#16 RSG#1 & #4 RSG#2 & #5RSG#3 & #6 LOAD DIRECTION 10 LVDT #2 STIFFENER SIDE 155 130 LVDT #3 STIFFENER SIDE 300 STIFFENER DEBOND BETWEEN STIFFENER & PANEL RELEASE FILM (47.5 x 50 mm) Applied load, out-of-plane displacements, and strains were measured during the testing Image Courtesy of Cooperative Research Centre of Advanced Composite Structures (CRC-ACS) COPYRIGHT CRC-ACS LTD. 2005 Copyright 2008 SIMILIA, Inc. LVDT #1 v Load -1 0 1 2 3 4 5 6 7 8 020406080100 120 140 160 180 200 220 240 260 Load (kN) Displacement (mm) LVDT #1 - ABAQUS LVDT #1- Panel 1 LVDT #1- Panel 2 LVDT #1- Panel 3 Out-of-plane Displacement Measurement Comparison Between Analysis and Test Panels *NOTE: Linear Variable Displacement Transducers (LVDT) LVDT #1 STIFFENER SIDE PARALLEL TO EDGE PARALLEL TO EDGE LSG#15 LSG#13 274 RSG#7 & #10 150 180 LOAD DIRECTION 70 155180 130 150 RSG#9 & #12 RSG#8 & #11 LSG#14 LSG#16 RSG#1 & #4 RSG#2 & #5RSG#3 & #6 LOAD DIRECTION 10 LVDT #2 STIFFENER SIDE 155 130 LVDT #3 STIFFENER SIDE 300 STIFFENER DEBOND BETWEEN STIFFENER & PANEL RELEASE FILM (47.5 x 50 mm) 17 Copyright 2008 SIMILIA, Inc. LVDT #1 - #2 v Load -1 0 1 2 3 4 5 6 7 8 020406080100120140160180200220240260 Load (kN) Displacement (mm) LVDT #1 - 2 - ABAQUS LVDT #1 - #2 - Panel 2 LVDT #1 - #2 - Panel 3 Out-of-plane Displacement Measurement Comparison Between Analysis and Test Panels *NOTE: Linear Variable Displacement Transducers (LVDT) LVDT #1 STIFFENER SIDE PARALLEL TO EDGE PARALLEL TO EDGE LSG#15 LSG#13 274 RSG#7 & #10 150 180 LOAD DIRECTION 70 155180 130 150 RSG#9 & #12 RSG#8 & #11 LSG#14 LSG#16 RSG#1 & #4 RSG#2 & #5RSG#3 & #6 LOAD DIRECTION 10 LVDT #2 STIFFENER SIDE 155 130 LVDT #3 STIFFENER SIDE 300 STIFFENER DEBOND BETWEEN STIFFENER & PANEL RELEASE FILM (47.5 x 50 mm) Copyright 2008 SIMILIA, Inc. LSG #15 Strain v Load -2000 -1500 -1000 -500 0 500 020406080100120140160180200220240260 Load (kN) Strain (uE) LSG #15 - ABAQUS LSG#15- Panel 1 LSG#15- Panel 2 LSG#15- Panel 3 Strain Comparison Between Analysis and Test Panels LVDT #1 STIFFENER SIDE PARALLEL TO EDGE PARALLEL TO EDGE LSG#15 LSG#13 274 RSG#7 & #10 150 180 LOAD DIRECTION 70 155180 130 150 RSG#9 & #12 RSG#8 & #11 LSG#14 LSG#16 RSG#1 & #4 RSG#2 & #5RSG#3 & #6 LOAD DIRECTION 10 LVDT #2 STIFFENER SIDE 155 130 LVDT #3 STIFFENER SIDE 300 STIFFENER DEBOND BETWEEN STIFFENER & PANEL RELEASE FILM (47.5 x 50 mm) 18 Copyright 2008 SIMILIA, Inc. LSG #16 Strain v Load -4000 -3500 -3000 -2500 -2000 -1500 -1000 -500 0 020406080100120140160180200220240260 Load (kN) Strain (uE) LSG #16 - ABAQUS LSG #16 - Panel 1 LSG #16 - Panel 2 LSG #16 - Panel 3 Strain Comparison Between Analysis and Test Panels LVDT #1 STIFFENER SIDE PARALLEL TO EDGE PARALLEL TO EDGE LSG#15 LSG#13 274 RSG#7 & #10 150 180 LOAD DIRECTION 70 155180 130 150 RSG#9 & #12 RSG#8 & #11 LSG#14 LSG#16 RSG#1 & #4 RSG#2 & #5RSG#3 & #6 LOAD DIRECTION 10 LVDT #2 STIFFENER SIDE 155 130 LVDT #3 STIFFENER SIDE 300 STIFFENER DEBOND BETWEEN STIFFENER & PANEL RELEASE FILM (47.5 x 50 mm) Copyright 2008 SIMILIA, Inc. VCCT Summary Good correlation achieved between analysis and experiment Combined with existing strong Abaqus composites and fracture functionality and built on the strong framework of Abaqus for general nonlinear capability, this capability is unique Abaqus is working with the composites community (Mil-17, ASTM D30, FAA Center of Excellence) to validate and verify analysis procedures for application of cohesive elements and VCCT to stiffness, strength, life, and damage tolerance of composite structures 19 Copyright 2008 SIMILIA, Inc. Simulating Delamination Using Cohesive Elements Cohesive elements are useful in modeling adhesives, bonded interfaces, and gaskets. Models separation between two initially bonded surfaces Progressive failure of adhesives Delamination in composites Idealize complex fracture mechanisms with a macroscopic “cohesive law,” which relates the traction across the interface to the separation Abaqus/Standard simulation of T-peel analysis Copyright 2008 SIMILIA, Inc. Element Technology Element types* 3D elements COH3D8 COH3D6 2D element COH2D4 Axisymmetric element COHAX4 Can be embedded in a model via shared nodes or tie constraints. Bottom face Top face *Cohesive pore pressure elements are also available. 20 Copyright 2008 SIMILIA, Inc. Element Technology Element and section definition *ELEMENT, TYPE = COH3D8 *COHESIVE SECTION, ELSET =., RESPONSE = TRACTION SEPARATION, CONTINUUM, GASKET , THICKNESS = SPECIFIED, GEOMETRY, MATERIAL = . Specify thickness in dataline (default is 1.0) Copyright 2008 SIMILIA, Inc. Element Technology Default thickness of cohesive elements Traction-separation response: Unit thickness Continuum and gasket response Geometric thickness based on nodal coordinates 21 Copyright 2008 SIMILIA, Inc. Element Technology Import of cohesive elements The combination of Abaqus/Standard and Abaqus/Explicit expands the range of applications for cohesive elements. For example, you can simulate the damage in a structure due to an impact event then study the effect of the damage on the structures load carrying capacity. Copyright 2008 SIMILIA, Inc. Constitutive Response Delamination applications Traction separation law Typically characterized by peak strength (N) and fracture energy (GTC) Mode dependent Linear elasticity with damage Available in both Abaqus/Standard and Abaqus/Explicit Modeling of damage under the general framework introduced earlier Damage initiation Traction or separation-based criterion Damage evolution Removal of elements 0 1 2 3 4 5 6 7 00.20.40.60.81 Mode Mix GTC Normal mode Shear mode Dependence of fracture toughness on mode mix Typical traction-separation response 22 Copyright 2008 SIMILIA, Inc. Constitutive Response Linear elasticity with damage Linear elasticity Defines behavior before the initiation of damage Relates nominal stress to nominal strain Nominal traction to separation with default choice of unit thickness Uncoupled traction behavior: nominal stress depends only on corresponding nominal strain Coupled traction behavior is more general *ELASTIC, TYPE = TRACTION, COUPLED TRACTION Copyright 2008 SIMILIA, Inc. Damage initiation Mixed mode conditions Maximum stress (or strain) criterion: Output: MAXSCRT MAXECRT Constitutive Response maxmaxmax ,1 n ts MAX NTS = 0 00 nn n n = Edit flag brings up the Specify Layer Controls dialog for Layer Data Control geometry at the turnaround region Specify wind angle parameters Plot wind angle CAD Data may be used to read in wind angle data from winding machine output Mesh Controls allow the user to override the global mesh control parameters on a layer-by-layer basis (eg. Hybrid elements for hyperelastic materials) Wound Composite Modeler (WCM) for Abaqus Winding Layout (contd) 37 Copyright 2008 SIMILIA, Inc. Example wind angle plot shows the geodesic (frictionless) and the non-geodesic (with friction) wind angle vs. radius for layer 3 (helical 1) Note the deviation from geodesic at the tangent line (R = 12.0) at a maximum reducing to zero at the turnaround (R= 1.95) Curve exponent controls this deviation along the dome length Wound Composite Modeler (WCM) for Abaqus Wind Angle plots The wind angle is used to compute angle- ply orthotropic material properties for each element or for each group of elements within a user-specified wind angle bin Because the laminate moduli are proportional to cos4,slight variations in the wind angle can have significant effects on the dome stiffness and resulting stresses and strains Example T700 : E1 (30)/ E1(35)= 1.61 E2 (30)/ E2(35)= 0.81 Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model Overall model geometry 24 in. ID x 24 in. long 3 primary helical layers 3 hoop layers 1 high angle transition helical Aluminum liner / Polar boss / Covers 1 Rubber shear-ply 2 hand layed-up doily layers Analysis Pressurize to 3000 psi yield liner in-situ (autofrettage) De-pressurize ( 0 psi) Results in compressive prestress between liner and composite From Part Instance Liner Composite Overwrap 38 Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) View near forward opening Rubber shear-ply doily and aluminum liner / polar boss Two cloth reinforcement layers (doilies) hand layed-up Void region where helical bridges over shear-ply / doilies Cover Plate Polar Boss / Liner Rubber Shear-ply Helical Layers Doily Reinforcement Layers Voids Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) View near forward tangent line Note bridging over hoop layers Aluminum liner Primary Helical Layers Hoop Layers High Angle Helical Layer 39 Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) Displacement Results of Liner only (scale factor = 1.0) 3000 psi0 psi Undeformed geometry Deformed geometry Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) Displacement Results 3000 psi0 psi 2-D axi-symmetric geometry revolved 180 deg for visualization only 40 Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) Wind Angle (UVARM1) for COPV with Aluminum liner Wind angle = 90 deg at the turnarounds Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) Fiber Strain (UVARM2) for COPV with Aluminum liner 41 Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) Transverse to Fiber Strain (UVARM3) for COPV with Aluminum liner Copyright 2008 SIMILIA, Inc. Finite Element Analysis Model (contd) von Mises Stress in Aluminum Liner at : 3000 psi0 psi (residual) 42 Copyright 2008 SIMILIA, Inc. Finite Element Analysis