LS-DYNA® Consulting
LS-DYNA is akin to FEA on steroids. It presents the greatest flexibility and power of any FEA based analysis software and the greatest challenges for the analyst to construct an accurate model. Predictive Engineering has over the course of the last ten years completed a number of highly successful LS-DYNA projects that have been experimentally correlated. Due to confidentiality, only a few projects are given within this section. The generation of accurate LS-DYNA models is the result of hard work, attending basic and advanced LS-DYNA courses in Livermore, CA, having a degreed analyst with a doctorate in mechanics and over 24 years experience with FEA, and a close working relationship with the Livermore Software Technology Corporation (LSTC) engineering team (and a bit of luck).
LS-DYNA is by far the world's best explicit analysis code for the simulation of severe nonlinear transient events. Model creation is done within Femap and then exported to LSTC's LS-Pre/Post for model tweaking and post-processing.
LS-DYNA Project Quickview
CASE STUDIES
Respirator masks have historically been designed with a lot of silicone rubber to slop over a range of faces. This works adequately for many facial sizes but not for all. For face profiles that don't follow the norm, the use of respirators can lead to a false sense of security due to air leakage or a contamination threat. The National Institute of Science and Technology has been engaged in a multi-year program to improve the safety and effectiveness of full-face respirator masks.
Under Federal Motor Vehicle Safety Standards (FMVSS) 210, 222 and 225; automotive and bus seats are tested under extreme conditions to ensure that the seat will not fail and cause human injury. Besides the requirement that the seat not be torn from the floor of the vehicle during a crash (FMVSS 210), the seat must also not be too rigid, or that is to say, we want the seat to act as an energy absorber during a collision (FMVSS 222). Lastly, new bus seats must also be able to support child car seats (FMVSS 225).
Objective: To understand the mechanics of aluminum bat/ball interaction.
Cargo nets are rather mundane industrial things. They are manufactured from nylon or polyester webbing with steel rings and hooks sewn into attachment points. We see cargo nets in the back of pickup trucks, tying down cargo on large trucks and, if we are passing by a military airport where cargo is being transported, cargo nets are everywhere there is a shipping pallet.
This simulation provided the first true glimpse of the completely transient impact behavior of digger-tooth system. The point (the digging part) is attached to the nose (interior supporting part) by deceptively simple arrangement of steel and rubber pins. The interaction of these pins creates the locking mechnism between the point and the nose. When working as designed - the point or tooth stays "locked" in place during the digging operation (think gigantic buckets and digging systems.
The genesis of this project came about to validate a prior consultants work indicating that the thread design of a new device would fail right at the design load of the instrument. Since the company had experimental data which strongly indicated a failure load of 2x the design load there was a whirlwind of debate as to whether to proceed to mass production or conduct an extensive redesign campaign. Although I entered this project with high confidence I soon realized what a quagmire I had entered. Initially I thought the analysis work could be accomplished using a standard implicit nonlinear code and after a few days of frustrating keyboard pounding I soon realized that I needed more horsepower.
The U.S. Department of Transportation (DOT) specification 49 CFR 173 calls out a rigorous series of testing procedures for containers that are used in the transport of hazardous waste. One such requirement is that the container survive a drop test from certain height The height of the drop test is determined by the weight of the container. As the weight of the container increases, the drop height decreases. As an example, a 50,000 lbf container must survive a drop from 12" onto its most vulnerable corner.
FEA Consulting