Real World Nonlinear Mechanical Applications
33
Real World Nonlinear Mechanical Applications
-
Upload
design-world -
Category
Technology
-
view
137 -
download
6
description
Until recently, most finite element analysis (FEA) applications undertaken by design engineers were limited to linear analysis which provides an acceptable approximation of real-life characteristics for most problems. However, occasionally more challenging problems arise that call for a nonlinear approach. In this webinar, you will hear about real-world nonlinear applications and case studies associated with Comsol’s and MSC Software’s customers. Viewers of this webinar will learn: – How nonlinearities in engineering systems arise from several sources including: – Material properties including multi-physics behavior – Geometry variations that involve large deformations and strains – Boundary conditions that could be continuously changing affecting the response
Transcript of Real World Nonlinear Mechanical Applications
Real World
Nonlinear Mechanical Applications
This webinar will be available afterwards at
designworldonline.com & email
Q&A at the end of the presentation
Hashtag for this webinar: #DWwebinar
Before We Start
Moderator
Laura Carrabine Design World
David Kan COMSOL
Presenters
Srinivas Reddy MSC Software
Real World Nonlinear Mechanical
Applications
Srinivas Reddy
February 29, 2012
Product Development Challenges
Can I build it? Is it durable? Is it crashworthy? Is it safe?
Can I test it? Will it perform to spec? Will it fail? Why did it fail?
CAE to Improve Product Performance
Pipe impact
Sports equipment
Bolt Loading
Shearing/Tearing
Seal analysis
Brake disk
CAE to Optimize Manufacturing Processes
Superplastic Forming Glass Forming
Forming Riveting
Cutting
Extrusion
Nature is Nonlinear
F
u Displacement
Load
Nonlinear Behavior
Linear Behavior
u
F
s
e Strain
Nonlinear Behavior
Linear Behavior Stress
Yield Pt. F F
Sources of Nonlinearities
• Materials o Metals, plastics, elastomers, powder metals,
shape memory
• Deformation o Buckling, folding
• Boundary conditions and loads o Contact, loads changing with deformation
• Multi-physics o Temperature effects, electromagnetics
Challenges of Nonlinear Analysis
• Material modeling
• Large deformation,
distortions and rotations
• Contact
• Performance
• Robustness
Material Modeling
• Metals
• Plastics
• Rubbers
• Shape memory alloys
• Composites
• Glass
• Concrete
• Powder materials
• Other non-metallic materials
• Customizable behavior
Aluminum Can Pull Tab
Plastic Bottle
Rubber Tire with Metal Rims
Composite Materials
Material Failure
• Metals o Ductile damage
• Elastomers o Material weakening
• Composites o Delamination
• Crack propagation
• Concrete o Brittle failure, crushing
Delamination
Crack Propagation Fatigue crack growth
Gear failure
Extreme Deformations
• Element formulations
• Appropriate stress/strain
measures
• Automatic local remeshing
o Mesh refining in high stress/strain
regions
• Automatic global remeshing
o Recreate a new mesh for the
entire part
Contact
• General large sliding
contact with friction
• Intuitive and easy set up
• Automatic contact
detection
• Remeshing
• Multi-physics
Performance
• Efficient solvers
• Parallel processing
o Excellent scaling
o Shared and distributed memory
• Domain decomposition method
o Linear scaling
o Benefit from networked desktop systems
o Solver large models
• Better use of hardware
o GPU
~75k Degrees of Freedom
MPI MPI MPI
Case Study: Column Shifter Boot • Business:
Automotive supplier
• Challenge: Accelerate the boot development to satisfy the requirements of OEMs by evaluating more design variants in less time
• Solution: Design variants are studied with Marc to predict the tear areas. For some design variants the analysis results are verified with tests
• Value: A boot design that meets the OEMs requirement was found in less time at less cost
17
Case Study • Business:
Leading producer of aluminum for engineered products
• Challenge: Avoiding tensile & compressive instability in formed parts
• Solution: Iterative Blank Design using Inverse Method with Marc
• Value: Accurate & efficient prediction of proper designs for forming operation in less time
18
Summary
• Nonlinear analysis challenges o Materials,
o Large deformations and distortions
o Contact and boundary conditions
o Coupling
• Technologies o Materials models,
o Contact modeling ease
o Physics simulation
o Automatic remeshing
o Performance
Nonlinear Mechanics in COMSOL A Multiphysics Perspective
David Kan
COMSOL, Inc.
February 29, 2012
The Multiphysics Approach
Structural Mechanics Branch
Geometry
Materials
Contact
Sources of Mechanical Nonlinearity
st
s
e
Geometric Nonlinearity
Small displacement
theory Green-Lagrange strains
Nonlinear Constitutive Laws
Hyperelastic constitutive law • Rubber
• Biological tissues
s
e
Elasto-plastic constitutive law • Metals
• Plastics
• Soils and concrete in compression
s
e
Hyperelastic Materials
Hyperelastic constitutive laws are defined
by the strain energy density, Ws • Neo-Hookean
• Mooney-Rivlin
• Murnaghan
s
e
Elasto-plastic Materials
s
e el
sy
Elasto-plastic materials are defined by two mechanical
behaviors: elastic and plastic
Nonlinear constitutive laws are defined above the yield
stress
In the plastic regime, there are irreversible strains
Contact
Source
Destination
How about
Multiphysics?
The Metelli Experience
Hyperelastic material law
Nonlinear geometry
Contact everywhere
Multiphysics
Multiphysics and Mechanics
• Creep
• Predefined couplings o Piezoelectric effects
o Acoustic-Structure Interaction
o Thermal-Electric-Structural Interaction
o Fluid-Structure Interaction
o Thermal-Structural Interaction
• General couplings
Thank You!
Questions?
Design World Laura Carrabine [email protected] Phone: 440.234.4531 Twitter: @wtwh_laurac
COMSOL David Kan [email protected] Phone: 310.441.4800 Twitter: @COMSOL_Inc
MSC Software Srinivas Reddy [email protected] Phone: 847.776.6740
Thank You
This webinar will be available at designworldonline.com & email
Tweet with hashtag #DWwebinar
Connect with
Twitter: @DesignWorld
Facebook: facebook.com/engineeringexchange
LinkedIn: Design World Group
YouTube: youtube.com/designworldvideo
Discuss this on EngineeringExchange.com
