N o n l i n e a r M u l t i - S c a l e M o d e l i n g o f A e r o s p a c e C o m p o s i t e s M a t e r i a l s & S t r u c t u r e s R o g e r A. A s s a k e r C E O, e - X s t r e a m e n g i n e e r i n g C h i e f M a t e r i a l S t r a t e g i s t, M S C S o f t w a r e Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 1
Composites Material Mix 2
3 Material Challenges Manage Material Data Generate Data (Cost & Time of Test) Manage, Trace, Protect (IP) Comply (Regulation) Model (composite) Materials, part & systems Nonlinearity: Progressive damage & failure Anisotropy Heterogeneity Process dependency
Systems Parts Materials Event 1 Event n Mat n System Use Actual Part (IP Protected) Mat 1 Use Actual Material Model (IP Protected) Parts Use Actual System (IP protected) Use Actual Material Model (IP Protected) Mat n Materials Use Actual System (IP protected) Use Actual Part (IP Protected) Mat 1
5 Data Import/Export/Access Search/Compare/Validate Trace/Protect Accurate Predictive CAE Neutral High Fidelity FEA Material Virtual Material Eng. Predict Multi-Materials Multi-Physics Process Automation Capture Processes Automate Processes
Exploiting Materials in Systems Design 3rd Party DB s Test Data Fit/Excel MaterialCenter Export Simulation.dll Reports Solvers Input / Characterization Materials Management Utilization
E-XSTREAM ENGINEERING Copyright e-xstream engineering, 2011 CONFIDENTIAL 7
e-xstream, The material modeling company Software & Engineering company 100% focused on advanced material modeling. Founded in 2003 A team of 30 (+ 4 TBH) 2 offices in Europe + MSC Hybrid sales channel 200+ major customers CAGR 04-11 of 56% An MSC Software Company (Sep 2012) Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 8
Customers Material Suppliers Plastics Composites, Automotive OEMs Tier 1 Aerospace Aero Structures (OEMs) Aero Engines Electric & Electronic Electronic Appliances: Electric : Connectors, transformers Defense Medical Devices Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 9
DIGIMAT, The material modeling platform Is The nonlinear multi-scale material modeling platform Used by Material Engineers Structural Engineers At Material Suppliers Tier 1 (Material Users/Any Industry) OEM (Material Users/Any Industry) For Material Engineering Accurate & Efficient FEA of Composite Structures Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 10
DIGIMAT Material Engineering Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 11
Nonlinear MicroMechanics Mean Field Finite Element E Global behavior Σ ( x) H : E r Localization r r a) b) c c ) : ( r Averaging ε r Local phase behavior r cr : r σ r Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 12
Process Material Structure Material Processing Injection molding Compression modling D-LFT Material Microsturcure Chopped fibers Nano,... Material Chracteristics Mechanical Thermal Electric,... Structural Performance Stiffness Strength Fatigue, Material Processing Drapage, AFP, PCM HP-CRTM Material Microsturcure Continuous fibers: UD/Woven Nano,... Material Chracteristics Mechanical Thermal Electric,... Structural Performance - Stiffness - Fatigue, Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 13
Nonlinear Multi-Scale Modeling Fibers Stress Carbon Fiber E 1 = 220 GPa E 2 = 15 Gpa G 12 = 22 GPa ν 23 = 0.2, ν 12 = 0.2 Smax =5.400 GPa Fully Coupled NL MicroMech Constituent Prop Process Effect Real MicroStr Micro Failure Matrix Strain Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 14
Motivation for Multi-Scale Modeling Continuous Fibers/Draping Carbon Fiber E 1 = 220 000 MPa E 2 = 15 000 Mpa G 12 = 22000 MPa ν 23 = 0.2 ν 12 = 0.2 Failure Epoxy UD Woven Failure CF Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 15
DIGIMAT Structural Engineering Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 16
Nonlinear Multi-Scale Modeling Microstructure & Macro Strain Macro Stress & Stiffness Matrix Micro stress, strain, failure 17
Structure Engineering Material Engineering Material & Structural Engineering Promising Material Candidates Improved MF Modeling Composite behavior Constituents Behavior Constituents Behavior Draping Inj. Molding Strong, 2-Way Coupling Copyright e-xstream engineering, 2011 - CONFIDENTIAL
C a s e S t u d i e s MATERIAL ENGINEERING Copyright e-xstream engineering, 2011 CONFIDENTIAL 19
Mechanical: Stiffness Matrix of CFRP Source: Copyright e-xstream engineering, 2011 CONFIDENTIAL 20
Thermal: Thermal Conductivity Materials : thermal conductivity (isotropic) Kerimid 601: 0.23 W/mK Al 2 O 3 : 30.7 W/mK 2-phase Microstructure : Kerimid matrix with Al 2 O 3 fibers matrix : Kerimid inclusions : Al 2 O 3 fibers volume fraction : from 0.0 to 0.4 AR = 6 orientation : random in xy-plane (Random2D) Copyright e-xstream engineering, 2011 21
Electric : Electric Conductivity Materials : electrical conductivity (isotropic) PE: 2.5 E-14 S/cm Carbon : 50 S/cm (effective particle*) Microstructure : 2-phase matrix : PE inclusions : Carbon VF: 0 50% AR: 1, 5.5 & 33 Orientation: Random3D * value obtained from composite with inclusion volume fraction 1.0 [Cai] 22
23 Curing of CFRP Defects generated in the material during processing Can eventually lead to failure of the composite Segmentation Matrix enrichment Pores Delamination
Curing of CFRP 24
25 Curing Analysis of CFRP DIGIMAT enables us to perform in depth studies of complex and realistic microstructures. As an invest into the future we base our simulation approach on the DIGIMAT software, both for our research and the education of a new generation of simulation engineers who will be experts in the modeling of materials. Prof. Vasily Ploshikhin, Airbus endowed chair for Integrative Simulation and Engineering of Materials and Processes (www.isemp.de)
C a s e S t u d i e s MATERIAL ENGINEERING Copyright e-xstream engineering, 2011 CONFIDENTIAL 26
Imposed force history Aero Structure: Barely Visible Damage CFRP 4-side clamped plate: Width : 4 in. (100 mm) Length : 6 in. (150 mm) Lay-up sequence : [45/90/-45/0] 3s 24 layers of UD Total thickness : 4.8 mm Materials : Carbon AS4 (source: Hexcel composites, www.hexcel.com) Longitudinal Young s modulus : 228 000 MPa Transverse Young s modulus : 6220 MPa Transverse shear modulus : 7600 MPa Tensile strength : 4278 MPa Epoxy 15 parts Bisphenol A-epichlorhydrine, 2 parts tri-ethylenetetramine (source: Rensselaer Polytechnic Institute, Troy, New York) Stress-Strain curve for Epoxy ElastoPlastic behavior : 35 Young s modulus : 1300 MPa Yield stress : 22.5 MPa Isotropic exponential hardening Microstructure : Unidirectionnal fibers Volume fraction of fibers = 57 % Stress (%) 30 25 20 15 10 5 0 0 1 2 3 4 5 6 7 8 Strain (%) Experiment Exponential hardening model Force (N) 14000 12000 10000 8000 6000 4000 2000 0 0 5 10 15 20 25 Time Copyright e-xstream engineering, 2011 CONFIDENTIAL 27
Aero Structure: Barely Visible Damage in CFRP (Accumulated Plastic Strain in Epoxy Matrix) Copyright e-xstream engineering, 2011 CONFIDENTIAL 28
Bird Impact on Composite Belly Fairing UD Woven Failure Epoxy Carbon Fiber E 1 = 220 000 MPa E 2 = 15 000 Mpa G 12 = 22000 MPa ν 23 = 0.2 ν 12 = 0.2 Failure CF Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 29
Bird Impact: Composite Belly Fairing Copyright e-xstream engineering, 2011
Macro & Micro Failure Indicators 31
32 Aero Engine: Ti/SiC Compressor Blade Turbine Blade: Centrifugal Cyclic Loading Material: Matirx : Ti- ElastoPlastic Reinforcements: SiC Elastic Short Fibers/Oriented
OUTLOOK Copyright e-xstream engineering, 2011 CONFIDENTIAL 33
Outlook Materials Long Fibers Thermoplastics Woven Composites Performance Fatigue Source: Lomov & Al. Chopped Fiber Continuous Fiber Creep Physics (longer term) More focus on electric conductivity (MD) Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 34
CONCLUSIONS Copyright e-xstream engineering, 2011 CONFIDENTIAL 35
M U L T I Digimat s Holistic Multi-Scale Modeling Materials Chopped Fibers: Short/Long Continuous Fibers Fillers Physics (Thermo)-Mechanical Thermal Electric Manufacturing Injection Draping Compression Performance Stiffness Strength Fatigue Technology Linear/Nonlinear Mean Field/FEA Micro/Hybrid
Digimat Value Proposition e-xstream is the Composite in: Design & Process of Composite Products Copyright e-xstream engineering, 2012 e-xstream CONFIDENTTAL 37