Know how it performs
and how long it lasts,
before you build it.
Multibody, vehicle dynamics and durability simulation for teams that build vehicles and machines.
DSIM Reference Study: a welded light-truck trailing arm, its 36.2 lb second redesign, through a 3 in pothole at 20 mph. Solved in Adams Solver.
Simulation work for
Six ways it pays for itself
Each one backed by a real program or a published DSIM Reference Study. Pick one to see the proof.
max- A light-truck rear corner at 20 mph, heading for a 3 in pothole.
- The tire drops into the hole and leaves the road. Its contact force falls to zero.
- The tire hits the far edge at 4,040 lbf, more than twice its static load. The arm's stress peaks 10 ms later.
- A test vehicle records the channels you instrumented, like this knuckle accelerometer. The model also reports the ones a test rarely gets, like this pivot load.
- Over the assumed road mix, this design's welds last about 140,000 miles, under half the target of 300,000 miles. The model found the shortfall and the fix: with a larger tube and a thinner wheel-mount plate, the arm is 2 lb heavier (38.2 lb) and reaches about 400,000 miles.
Peaks during the strike: knuckle acceleration +15.9 g, pivot load 2,200 lbf, weld toe stress −31.5 ksi.
Tire contact force, lbf
DSIM Reference Study, second redesign (36.2 lb), 1.1 s of real time. All values simulated.
What the numbers mean
Acceleration: vertical, gravity removed. Arm stress: von Mises on the arm's visible surface, leaving out 0.3 in around each weld toe; its peak sits beside the governing weld, where the weld method, not this number, sets the life. Weld toe: IIW hot-spot stress, compression negative. The frames and values on screen are from the study's first round of runs: with the final solver settings this strike's tire load is unchanged, and the acceleration, pivot load and weld stress run about 4 to 6 percent higher. The lives in miles are from the final runs.
Real loads for stress and fatigue
Every joint force at every instant, fed straight into FEA and durability work.
76x
weld life after three redesigns, found before any part was built
Reference study
Welded trailing arm, light-truck rear corner
- Problem
- Rough roads and impacts fatigue welded suspension arms; testing finds the weak spot only after hardware cracks.
- Modeled
- A flexible arm and an enveloping tire on eight road events, with stress at every node and every weld toe.
- Result
- Original arm: about 5,200 miles of weld life. Final design: about 400,000 miles.
Two client programs
Validating an autonomous tracked vehicle before cutting metal
Stratom, Inc.
- Problem
- No prototype yet, and a high cost for a wrong first build.
- Modeled
- Full-vehicle multibody model with track systems over terrain and obstacles, transient stress on the flexible frame.
- Result
- Design changes made from the model; the prototype build went ahead on time and under budget.
Predicting bucket loads on a machine that did not exist yet
A heavy-equipment OEM
- Problem
- Hydraulics to size at concept stage, and no machine to measure.
- Modeled
- Discrete element material simulation coupled to the machine model through the dig cycle.
- Result
- A power envelope for sizing the hydraulics while the design was still open.
Darren Simoni, Principal
Building multibody models since 1996: Adams Solver, durability and loads, ride and handling, Magic Formula tire models, wheeled and tracked vehicle dynamics, FEA, and correlation of models to physical test.
Post Falls, Idaho.
Two kinds of teams call DSIM
Some want a design proven in simulation before committing to hardware. Others already built the machine and have a problem they can't explain: a vibration, an instability, a failure that testing alone won't diagnose. If deep multibody simulation or vehicle dynamics expertise isn't part of your core team, DSIM can help with both.
How a first project starts
- A free 30-minute callThe machine, the question and the decision it supports.
- A short scope noteWhat will be modeled, what is assumed, what you receive and when.
- The model and the answerBuilt, checked against test data, hand calculations or published measurements, and delivered with its assumptions stated.
A first project can be a pilot: one real question, scope agreed before work starts, no software to buy.
NDA-ready and US-based.
“Darren brought our simulation capacity to an entirely new level. We engineered an innovative hybrid mining shovel and validated new design and controls concepts through simulation, without spending excess money on tests.”