Finite Element Analysis in Crashworthiness Cases Expert Article

This article discusses Finite Element Analysis (FEA) and how it can be used in automotive product liability cases. The automotive experts at Robson Forensic have firsthand industry experience using FEA to demonstrate a vehicle’s ability to protect its occupants in a crash and can apply that same expertise to legal disputes involving vehicle crashworthiness.

What is Finite Element Analysis?

Finite Element Analysis (FEA) is the use of computers to perform thousands of calculations on models of vehicles (or parts of vehicles) to simulate how they will behave in real world conditions. FEA can be a powerful tool in automotive product liability cases, enabling experts to simulate how a vehicle was designed to perform under incident conditions and then re-running models to demonstrate how specific design changes would affect vehicle performance or crash survivability.

FEA is known by many terms such as CAE (Computer Aided Engineering), computer simulation, or digital twin. FEA has a multitude of applications beyond crash testing that include static, dynamic, acoustic, fluid, forming or thermal type load cases.

Case Types that could benefit from FEA

Typical automotive cases where the use of FEA could be beneficial include product liability claims related to the structural performance of a vehicle: 

• Fuel tank integrity - Where a vehicle fire has been caused due to the lack of structural protection.
• Occupant protection - Where excessive structural deformation resulted in intrusions into the survival space, causing occupant injuries, or passengers were injured as a result of being exposed to excessive accelerations or decelerations during a crash.
• Component failure - Where a safety related component has failed causing a loss of control or failure to protect the occupants, i.e. steering link breakage or seat belt mount failure.
• Battery pack integrity - Where an electric vehicle fire has been caused due to the lack of structural protection.  

Automotive Product Development using FEA

Traditionally, automotive OEMs (original equipment manufacturers) used vehicle prototypes and testing as the primary method to validate their designs. However, prototypes are extremely expensive, one full vehicle can cost over $250,000, and so is the cost of testing them, particularly when the tests are destructive.

The growing complexity of modern vehicles made it prohibitively expensive to perform sufficient physical testing or to perform the calculations necessary to determine whether the various component and assembly designs would meet safety and other requirements.  As a result, the automotive industry has embraced FEA tools and has incorporated them into their product development processes.

Today, OEMs have managed to reduce the number of build and test phases and the number of prototype vehicles that they build by intensively utilizing FEA while at the same time improving crash worthiness and other performance requirements.

Leveraging FEA in Vehicle Crashworthiness Cases

Building accurate FEA models requires a significant investment in human and computing resources. Full vehicle models are typically comprised of millions of elements and are built over many months using dedicated OEM engineers, suppliers, and FEA service companies. The models utilize data collected through component, material, and joint testing in addition to component forming simulation result mapping. The results generated by analyzing the FEA models are compared to physical test data gathered during the prototype and production build phases. 

As such, it would be impractical to develop FEA models from scratch for most legal disputes, but there may be existing models in the public domain or available through the discovery process that can be leveraged on individual cases. 

Obtaining FEA Models through Discovery

In some vehicle product liability cases, it could be possible to obtain the OEM’s FEA model of the relevant vehicle and load case. For example, if a vehicle had performed poorly in a roll over crash, obtaining the FEA roof crush model could be beneficial to the case. 

OEMs build FEA models to simulate both the FMVSS 216a and IIHS roof crush test modes that require passenger vehicles roof strength to meet specific requirements. These models would typically be correlated to physical tests that the OEM performs to certify that the product meets regulatory requirements.

Robson Forensic FEA Capability

Robson Forensic has access to the simulation tools and computing power to enable full vehicle or system level FEA model analysis.

In a product liability case, we can use FEA to establish the design changes that could have been made to improve safety or vehicle performance. For example, by increasing the body panel thicknesses, or using different material types or by adding reinforcements. The FEA analysis can provide compelling data of the revised design performance and provide visual animations that can easily explain the benefits of such changes to a jury.

Vehicle Crash Expert Witness Investigations

From complex crash reconstruction to developing demonstrative evidence for court testimony, the transportation experts at Robson Forensic are well equipped to assist in your investigation. Our experts have in-depth knowledge of how gasoline and electric vehicles are designed and built, they are fluent in the regulations affecting trucking operations, and have designed, built, and maintained our nation’s transportation infrastructure.

For more information, submit an inquiry or call 800.813.6736.

Featured Expert

Christopher D. Roche

Automotive Engineer & Crash Expert

Christopher Roche is an automotive engineer with nearly 30 years of professional experience working for major vehicle manufacturers, specializing in the design of vehicle structures to protect… read more.