Multi-Physics Crash, Rollover, NVH & Suspension Simulation

How a Small Engineering Firm Ran One of the Most Rigorous Automotive Safety Simulations We’ve Seen and Published the Results

What We Found When We Worked on Fluxiss’s Automotive Work

Fluxiss runs a full multi-physics crash, rollover, NVH, and suspension kinematics study in two industry-standard solvers simultaneously, quietly, and without a lot of noise, then publishes a head-to-head correlation study. That’s not a typical portfolio move. That’s something you do when you’re trying to answer a real engineering question.

So let’s walk through what they actually did, what they found, and why it matters if you’re running an automotive safety or motorsport program anywhere from Detroit to Dubai.

The Real Problem Nobody Talks About in Vehicle Safety Programs

Here’s something we’ve read about repeatedly in automotive engineering discussions: crash simulation programs almost always run over time and over budget, not because the engineers are slow, but because running every load case through two solvers is expensive and takes forever. According to SAE International’s published literature on simulation workflow efficiency, dual-solver validation is considered best practice for safety-critical vehicle programs, but most teams skip it because of the cost.

For a client, Fluxiss was tasked with delivering validation in more than just crash scenarios; it included a rollover event, NVH targets, and suspension kinematics, too. The engineering team required fewer answers, and they wanted to know if there were the same answers from both LS-DYNA and RADIOSS; they do not want to have to rerun all the data in the future using LS-DYNA.

That’s the problem they set out to solve. Straightforward. Practical. And harder than it sounds.

LS-DYNA vs RADIOSS: The Crash Simulation Showdown That Actually Delivered Answers

What They Ran And Why Each Load Case is Important

The simulation scope we studied covers what we’d call a complete safety envelope:

• Frontal crash against both rigid and deformable barriers
• Rear impact focused on intrusion depth and energy absorption
• Side collision with B-pillar deformation and occupant space evaluation
• Vehicle rollover covering roof crush and lateral stability
• Deformation contour mapping at key timesteps: 0.025s and 0.057s

Each of these corresponds to a real-world regulatory scenario. The FMVSS (Federal Motor Vehicle Safety Standards) and Euro NCAP test protocols — which are the benchmarks used in the US and across Europe, respectively require exactly this kind of multi-scenario validation before a vehicle goes near a production line.

What Fluxiss did was set up identical models in both LS-DYNA and RADIOSS and run them in parallel. Then came the hard part: the correlation study.

Correlation Study Is the Most Important Thing in This Portfolio

Solver Agreement at Every Timestep That’s Not Easy to Pull Off

We’ve read enough simulation engineering papers to know that getting two different solvers to agree on crash deformation at every timestep is genuinely difficult. Each solver has its own contact algorithms, material card implementations, and element formulations. Small differences compound fast in a crash event.

A significant correlation between solvers for both crash and rollover load cases is reported by Fluxiss; here, the deformation contours, the energy absorption curves, and deformation location depths correlate. They also found out which meshing strategies and material card settings gave the best agreement, which is useful (and more interesting than the results) because it will allow a future engineering team to ‘re-invent’ the setup.

To make it public so people can use it again and again, that’s the domain of methodology documentation, as opposed to a one-off simulation project.

NVH Analysis: The Part of the Study Most Portfolios Skip

Noise, Vibration, and Harshness Results That Matched Across Both Solvers

NVH analysis is like, studying engineering portfolios, the most commonly skipped element in automotive simulation case studies. It’s complex, it’s frequency-dependent, and it requires a very different setup compared to crash work.

Fluxiss ran a full-vehicle NVH analysis covering modal response and frequency response functions. The result: frequency response peaks aligned between LS-DYNA and RADIOSS within acceptable tolerance.

This matters more than people realize. NVH directly affects customer satisfaction ratings, and according to J.D. Power’s Vehicle Dependability Studies, noise and vibration issues consistently rank among the top complaints in new vehicle ownership. Engineering teams in Stuttgart, Coventry, and Abu Dhabi working on vehicle refinement programs need this kind of simulation confidence before they commit to a structural design.

Suspension Kinematics: Where the Real Vehicle Dynamics Intelligence Lives

Camber, Toe, Caster, Roll Center: All Validated Across Travel

The suspension kinematics work in this study is what’s going to catch your attention most. Fluxiss ran five sweep conditions:

• 4mm bump
• 4mm pitch
• 4mm roll
• 0.5° roll
• 10° steering

They tracked camber vs. heave, camber vs. roll, kinematic roll center position in X/Y/Z across the travel range, and toe and caster angle stability under dynamic loading.

For anyone building a formula car for SAE competition or designing a performance suspension system for a road vehicle program, these are the exact parameters that determine whether a car actually handles the way the simulation predicts. The fact that both solvers returned matching kinematic results gives the engineering team confidence that the underlying model is correct, not just that one solver is producing plausible-looking numbers.

What This Means for Engineering Teams in the US, UK, Europe, and the Gulf

Multi-Physics Simulation at This Depth Is Now Accessible Beyond the Tier-1 OEMs

The broader point here is accessibility. This kind of multi-physics simulation workflow, crash, rollover, NVH, and suspension kinematics, dual-solver validated, used to be something only OEM-level organizations with massive internal teams could execute. Fluxiss is doing it as a consultancy, serving clients from their Sheridan base and Glasgow hub, with engineering execution across Pakistan and the UAE.

That means a motorsport team in Birmingham, a vehicle startup in Dubai, an EV company in Detroit, or a niche manufacturer in Karachi can now access the same simulation rigor that a major automotive program uses without building internal capabilities from scratch.

The Result That Actually Mattered: A Validated Dual-Solver Workflow

At the end of this study, what Fluxiss delivered wasn’t just a report. They delivered a validated methodology, specific meshing settings, material card configurations, and correlation benchmarks that their clients can use to run future design iterations faster and with more confidence.

That’s the engineering outcome that saves money in a real program. Not the simulation itself, but the workflow that comes out of it.

Precision Simulation Is the Cheapest Crash Test You’ll Ever Run

Fluxiss built something genuinely useful with this case study. Not just a demonstration of software capability, but a reproducible, correlation-validated workflow that answers the kind of question real automotive programs actually face.

If you’re running a vehicle safety program, developing a formula car for an SAE competition, or trying to determine whether your suspension kinematics meet your targets before you build hardware, this is the kind of simulation work that removes guesswork from the process.

Real crash tests cost hundreds of thousands of dollars per event. A well-run simulation study costs a fraction of that and tells you more. The engineering teams that figure that out early in Los Angeles, London, Riyadh, or Lahore are the ones who hit program milestones without the expensive surprises.