George Laird's blog

LS-DYNA: Observations on Composite Modeling

This is the 2nd in a series of informal articles about one engineer’s usage of LS-DYNA to solve a variety of non-crash simulation problems. The first was on LS-DYNA: Observations on Implicit Analysis, the third was LS-DYNA: Observations on Explicit Meshing, and the fourth was LS-DYNA: Observations on Material Modeling

My academic background is in micro-mechanics and I have a good understanding of how many angels can dance on the head of a pin. A lot of my academic work was on fracture mechanics from a theoretical aspect and whenever I got into the laboratory, it was often a crazy chase in trying to correlate real-world fracture behavior to numerical models. I find the same behavior in composites. Ask ten composite experts and one can get 20 opinions. We have a myriad of theories that I don’t even want to start mentioning. My favorite reference to the uncertainties of composite analysis is that of the World Wide Failure Exercise (WWFE) where brave scientists were given raw composite data and had to make failure predictions without having access to the experimental data. Given that they couldn’t curve fit or pick their preferred layups or whatever, the reality was that theory could match experiment within 20%. This really isn’t as bad as it sounds since experimental data has a typical range of 10%.

LS-DYNA: Observations on Implicit Analysis

This is the 1st in a series of informal articles about one engineer’s usage of LS-DYNA to solve a variety of non-crash simulation problems. The second was on LS-DYNA: Observations on Composite Modeling, the third was LS-DYNA: Observations on Explicit Meshing, and the fourth was LS-DYNA: Observations on Material Modeling

I’m doing more and more implicit work with LS-DYNA and would like to share some of my observations on its improvement over the last couple of years. You might be surprised how far Mortar Contact and linear dynamics (e.g., PSD and general NVH) have come. This article provides a quick little overview of what is happening with LS-DYNA implicit, some tips and tricks we have learned along the way, and resources that are available to sharpen up your skill set.

Why Bother?

10th European LS-DYNA Conference, Wurzburg, Germany

This biennial LS-DYNA conference was held in Würzburg, Germany and was hosted by DYNAmore of Germany. Predictive Engineering was represented by Adrian Jensen and George Laird where we presented our new LS-DYNA MPP Program Manager interface. Key topics of interest were the new CFD capabilities within LS-DYNA, extensive code improvements toward increased scalablity (MPP and hybrid SMP/MPP) and advanced composites modeling. Besides over 170 papers (see DYNALook for a digital archive of the papers) concurrent workshops were given on implicit, CFD, composites, dummy positioning, etc.

As with all LS-DYNA conferences, the social activities were outstanding with beer gardens, gala dinners and lots of time to discuss engineering simulation with the over 450 attendees. If you are using LS-DYNA or interested in nonlinear, transient analysis, the LS-DYNA conferences are great venues to network, learn new skills or just expand your horizons.

 

10th European LS-DYNA Conference / Predictive Engineering LS-DYNA Consulting Services

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