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Plasticity, Buckling, And Contact Solved Before Tooling, Not In Field Returns
Send your CAD and loads. Get a roadmap to a design that holds. Free.
Linear finite element analysis (FEA) assumes small deflections, elastic material, and contacts that never change. Real parts don't behave that way near their limits. Nonlinear analysis FEA models yielding, buckling, large deflection, and contact that opens, slides, or closes.
When a linear model is the only evidence, teams do one of two things. They add thickness and weight until the margin looks safe, and pay for it on every part. Or they trust the number and find the failure in test, where every redesign costs a prototype and weeks.
As your nonlinear FEA consultant, PPS uses FEA nonlinear analysis to find the real limit of your design. You get a part that is as light and as cheap as it can be while still meeting its loads, and you know why. Where heat or vibration drives the load, our FEA thermal analysis services and vibration analysis services work from the same model.
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Linear FEA not matching test results: it passes, the part cracks
The model and the bench disagree, and nobody can say why.
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Stresses exceed yield in your linear model
You can't tell if local yielding is acceptable or the start of collapse.
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Thin walls, shells, or struts under compression
They may buckle long before the material yields.
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Bolted joints, seals, or press fits
Contact that opens, slides, or closes changes the load path.
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Rubber, plastics, or elastomers
Large strains break small-strain assumptions.
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A part you overbuilt because nobody could prove a lighter one
Extra material you pay for on every unit.
Cost you carry
Decision it lets you make
Result
Unit cost
Material & weight
Decision
Know the real yield and collapse margin, then remove material you can prove you don't need.
→
Result
A lighter, cheaper part that still meets its loads.
Development
Prototypes & testing
Decision
Predict plastic deformation, buckling, and contact before the build, and go to test to confirm.
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Result
Fewer prototype loops and shorter test phases.
Tooling
Rework & redesign
Decision
Find the failure mode in simulation and fix the geometry before steel is cut.
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Result
No redesign after first article; tooling is built once.
After launch
Field failures & warranty
Decision
Model the real loads, cycling, and contact, and release with margins you can document.
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Result
Fewer returns and claims, and a design you can defend in review.
01
A design that meets your loads at the lowest total cost, delivered as production-ready CAD and drawings
02
FEA results and margins you review and approve at each gate, before anything moves to prototyping.
03
You own the IP by default, set in your contract.
04
If we missed it in our QC, we fix it. If your supplier can't make the part within three years, or supply dries up, we fix that too.
You send
What we need to start
CAD, native or STEP
Loads and operating conditions, or how the part is used
Material specs or test data, if you have it
Targets: weight, cost, life, or code
Failure history, if a part already failed
→
You get
What you hold at the end
The optimized design: CAD and drawings ready for production
Models and results you reviewed and approved
Documented margins or code compliance
Test correlation, when testing is in scope: a partner lab or yours
A roadmap for what comes next, and a team that stays with you
We price to the value we deliver, not the hours we log. If the value isn't there for you, we'll say so in the assessment.
Pressure Vessel · Industrial Client
Before
Wall thickness set by conservative linear checks. Extra material on every vessel.
After
Elastic-plastic analysis to ASME BPVC Section VIII, Division 2 proved the real collapse margin.
15%
Thinner wall
Div 2
Design by analysis
0
Code margin lost
We review your project scope and the CAD, loads, and history you have, and screen which nonlinearities matter.
Scope, targets, and gates, from where you are to where you need to be.
Nonlinear FEA and CAD iterations, with testing when needed.
The design, drawings, and models, second-checked in our QMS.
We stand behind the design through production and supply issues.
PPS engineers run FEA, CFD, and DFMA as one loop. Nonlinear results set real margins, CAD changes follow, and manufacturing cost is checked before tooling. The design you approve is the design that ships, and the one you pay for once.
Small-strain, elastic, bonded contact
Or add thickness until it does
Tooling and test article paid for
The failure shows up on the bench
New geometry, new prototype, new test
Which nonlinearities matter here
Plasticity, contact, buckling
Geometry refined to real margins
Second engineer verifies the model
Build once, to confirm
Every prototype loop you fund is margin lost. Get a free roadmap.
Get Your Free RoadmapPost-buckling and plasticity margins documented for review, so flight parts are both light and proven.
Lighter parts, proven.
Applications
Post-Buckling
Composites
Plasticity
Bolted Joints
Plastic strain and contact modeled before the first crash sled, so structures absorb energy as designed.
Pass the sled test once.
Applications
Crash Energy
Plastic Strain
Contact
Elastomers
Impact, yield, and bolted-joint contact solved for buckets and frames that must survive remote duty.
Stop costly downtime.
Applications
Impact Loads
Weld Yield
Bolted Joints
Fatigue
Hull panels and subsea housings checked for collapse and buckling under real pressure before the build.
Pass class review first.
Applications
Hull Collapse
Buckling
Subsea Housings
Class Rules
FEA, CFD, CAD, DFMA, and testing under one roof. Engineering is a team sport, and you get the whole team.
One team, every skill.
Under One Roof
FEA
CFD
CAD
DFMA
Testing
Veteran-owned SDVOSB status gives defense and federal buyers a set-aside path to proven engineering.
Verify our SDVOSB status.
Credentials
SDVOSB
VOSB
CAGE 8ZK73
NAICS 541330
Missed something in our QC? We fix it. Supplier can't make the part within three years? We fix that too.
Support for the long run.
We Fix
Our QC Misses
Supplier Gaps
Supply Chain
We price to the value we deliver, not hours logged. You buy a design that works, not more iterations.
Pay for the result only.
Collections
Gold
Platinum
Diamond
When does my design need nonlinear analysis FEA instead of linear?
Your design needs nonlinear analysis FEA when a linear model can no longer describe how the part behaves near its limits. Linear FEA assumes small deflections, elastic material, and contact that never changes. Real parts break those rules. That is the difference between linear and nonlinear analysis in FEA. Watch for five signs. Stresses in your linear model exceed yield. Thin walls, shells, or struts carry compression and may buckle first. Bolted joints, seals, or press fits open, slide, or close under load. Rubber, plastics, or elastomers see large strains. Or the part is overbuilt because nobody could prove a lighter one.
Any one of these makes the linear number a guess. A guess turns into extra weight on every unit or a failure on the test bench. The NAFEMS nonlinear analysis resources explain when each effect matters. PPS reviews your project scope in a free assessment and tells you which nonlinearities your design actually needs. If a linear model is enough for your part, we say so and explain why.
Which FEA software and CAD formats do you work with?
Our nonlinear analysis FEA work runs in ANSYS Mechanical, Abaqus, and LS-DYNA. We pick the solver that fits the physics. ANSYS nonlinear analysis and Abaqus handle plasticity, contact, and buckling with implicit solvers. Explicit dynamics in LS-DYNA covers impact and crash events. Tell us which solver your team uses. We accept native CAD from SolidWorks, CATIA, NX, Creo, Inventor, and Fusion 360, plus neutral formats: STEP, IGES, Parasolid, and ACIS. Broken geometry wastes time on many projects, because the mesh inherits every gap and sliver in the model. NIST's STEP File Analyzer can check a neutral file for errors before you send it.
We clean and check your geometry before meshing, so the analysis runs on the part you designed. If you already have FEA models, send them. We can review them, extend them to nonlinear, or rebuild them where the assumptions don't hold. For loads driven by vibration, our vibration analysis services work from the same models. Native model files are included at delivery, so your team can rerun any case.
What do you need from us to start?
To start a nonlinear analysis FEA project, send what you have, in whatever format your team already uses. That usually means CAD, native or STEP, and the loads or a description of how the part is used. Add material specs or test data, your targets, and any failure history. Missing data is a common reason engineering projects stall. A model built on guessed inputs gives a guessed answer, and a guessed answer can cost a prototype. That is why we don't start the work until every data set is in. For gaps in material data, NIST material measurement data is a good first stop.
Once your data is in, the first step is a free assessment of your project scope. We confirm what the work can and can't answer, and tell you what is still missing. Then we send a roadmap proposal with scope, targets, and approval gates. Every project is scoped on its own, so the roadmap sets the schedule, not a stock promise. NDAs are available before you share any files.
Who owns the design and the models?
You own the IP from your nonlinear analysis FEA project by default, as set in your contract. That covers the design, the drawings, and the models. Some firms keep the models or license them back to you, so every later change sends you back to them, at their price. That locks your product to one vendor. It also makes design reviews harder, because your team can't open the evidence behind the decisions. Your customers may ask for that evidence too. Export-controlled programs add another layer. The State Department ITAR guidance sets the rules for defense data, and a loose handoff can break them.
At PPS, the IP transfers with the solution, and nothing is held back to tie you to us. You receive the native CAD, the drawings, the simulation model files, and the documented results. Your engineers can check the work, rerun a load case, or hand the package to a supplier. We sign mutual NDAs before any data is shared, and we match your export-control rules from the start.
What happens if a prototype fails in test?
If a prototype fails in test, we find out why and fix the design. With nonlinear analysis FEA from PPS, you approve the data at each gate. So a test result is checked against predictions you have already seen, not against a black box you can't open. Hard engineering carries unknowns. Real loads, material lots, and assembly effects never match a model perfectly. A failure in test is data, because it shows which assumption was wrong. That data improves the model and the design. NASA's standard for models and simulations sets out how to judge whether a model's results can be trusted.
When testing is in scope, our design validation services plan the test to confirm the margins that matter most. Then we correlate the model to the results. If the miss was ours, because something slipped through our QC review, we fix it. If the test finds a condition nobody knew about, we scope the change with you and update the roadmap. Either way, you get a clear answer.
How is a nonlinear analysis FEA engagement priced?
We price every nonlinear analysis FEA engagement to the value it delivers, not the hours we log. Hourly billing rewards extra iterations. The meter keeps running whether or not the design improves. So the cheapest quote can become the most expensive project once rework shows up. Federal buyers know this risk well. The Federal Acquisition Regulation notes that a time-and-materials contract gives the contractor no positive profit incentive for cost control or labor efficiency. Our incentive runs the other way: get the design right the first time. We engage by fit, not as a ladder, so you start where your need is.
Gold (from $35K): you have one project and need help with it. Platinum (from $15K/mo): you have recurring work at a steady rhythm. Diamond (from $800K/yr): you have a long development program, often multi-year. Gold is never required, and these are starting points, not quotes. We price to the value we deliver, not the hours we log. If the value isn't there for you, we'll say so in the assessment.
Not sure linear is enough? Send the model. Get a free roadmap.
Send your CAD, loads, and targets. We review your project scope in a free assessment and reply within one business day with next steps.
On-site assessments that require travel are quoted separately.
