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Latest articles
Speeding up numerical studies using Discrete Optimization in LS-OPT
In an earlier post on simulation based product design we saw that in many cases a large portion of effort early on in the design cycle is usually spent on …
Sinusoidal Motion using *DEFINE_CURVE_FUNCTION
Here is a simple way to prescribe sinusoidal motion using *DEFINE_CURVE_FUNCTION. *PARAMETER ramp, 10.0 rfreq, 600 rshift, 0.0 *DEFINE_CURVE_FUNCTION …
Unloading Behavior in MAT_083
There are three different ways to model unloading behavior when using material model MAT_083. They are graphically depicted below (these figures may appear …
Time Integration, Characteristic Length, and Mass Scaling
A short presentation on the Explicit and Implicit time integration schemes which I use in my advanced LS-DYNA class is included here. Its a evolving …
Stress Relaxation in Viscoelastic Material Models
LS-DYNA allows several ways to model of stress relaxation often seen in viscoelastic materials when subjected to a sudden constant strain. The methods to …
Free LSTC USSID
A modified version of the NHTSA finite element model of the USSID is now available at no charge. LSTC USSID version 1.0 (LSTC FTP site) LSTC USSID
SPH Contact Definitions
SPH is now widely used in several high strain-rate and large-deformation problems which may otherwise be difficult to simulate when using traditional mesh …
Interface Component Analysis
Interface component analysis is a unique feature that helps to speed design variation studies for non-structural components using a model fragment of the …
MultiStage Dependent or Independent Simulations using *CASE
A powerful feature of LS-DYNA v970 and beyond that has yet to gain widespread popularity is the *CASE keyword. Here are two examples to highlight the use …
Modeling Off-Axis Dependent Yield Stress for Honeycombs using MAT_126
Honeycomb cell structures are popular among weight conscious designers due to their high strength to weight ratio. In the automotive space, aluminum based …
Choice of Rigidwall Treatment
There are two different methods that are available in LS-DYNA to treat nodes impacting a rigidwall (also referred as stonewall). The first method, which is …
Best Practices for Building Flexible Models with Reduced File Sizes
As LS-DYNA model sizes continue to grow, there is a greater need to reduce the file sizes or rather the model footprint. If good modeling practices are …