Reference Project: Structural Simulation of a Human Body Model

Applying High Detail Finite Element Analysis to Improve Safety

Structural simulation of the human body is neither an end in itself nor a tool for creating spectacular images. It is a tool to understand mechanical processes in the body that can only be captured experimentally to a limited extent or with great effort. In vehicle safety, biomechanics, sports, and defense industry the core question is the same: How do loads act on the human body, where do injuries originate, and what can be changed in geometry, material, or boundary conditions to prevent injuries or at least mitigate them?

Common whole-body models such as THUMS or GHBMC provide a solid basis for this. They are not just outer shells; they represent anatomy in detail—bones, ligaments, muscles, adipose tissue, and organs—modeled separately and coupled via realistic contacts. Geometry typically comes from CT/MRI and surface scans; material properties are derived from tests on tissue and bone specimens, often with pronounced nonlinearity and strain-rate dependence. What matters is that these models are validated against experimental data, from rib bending tests and thorax compression to complete accident scenarios.

Where is the practical value? An experiment shows that something happens; simulation shows how and why. We can observe motion sequences, load paths, pressure peaks in organs, and strains in the skeleton. We can identify whether a relevant quantity is driven by geometry, friction, contact stiffness, damping, or inertia effects. These insights let us build and improve variants purposefully,  instead of changing parameters at random, with the goal of minimizing injury risk.

FEA Simulation of an Object hitting an Human Body

See the following example of a Finite Element Model of a Human Body: An 8-cm steel ball (uff!) with initial velocity strikes the chest of a standing person. In an explicit dynamic simulation using the solver LS-Dyna, the sequence from first contact through maximum intrusion to rebound can be observed without gaps.

The simulation shown here uses the THUMS human body model, originally developed by Toyota. The figure shows the simulation model in detail. The model exists in different versions, which vary by gender, body size, and posture (seated as occupant or standing as pedestrian). In this case, the standing model, originally developed for simulating pedestrian accidents, is used.

If the model is to be used in a different posture, it must first be morphed. In cases of larger deformations, a positioning simulation must be performed beforehand.

The FE simulation proceeds in two steps:

1. Gravity is applied so that the person stands steadily on the ground and is appropriately preloaded. This step can be performed either by dynamic relaxation or by an implicit simulation.
2. The ball impacts the human model at an initial velocity, which is simulated using an explicit dynamic simulation approach.

Initially, local deformation at the impact point dominates. Then, the energy is transferred and distributed through the ribs, which bend and transmit energy into the internal organs. The strains shown indicate that multiple ribs will fracture. Additionally, pressure values shown in indicate serious injury to the lungs and heart.

Applying Years of Expert Know-How in Finite Element Analysis

For injury assessment, the data and thresholds are crucial. Here these are strains and stresses in the ribs to estimate fracture risk, deformation and pressure levels in the lungs and surrounding tissues to assess contusion risk. Velocities, accelerations, and deformations can be compared to available test data to align results with known thresholds. Based on this, one can evaluate whether changing the impact position or angle, or adding protective equipment, truly reduces injury risk or merely shifts the injury pattern. From this point onward, the simulation model can be used, for example, to study the effect of protective gear and optimize it.

For such statements to be reliable, advanced simulation methodsand the appropriate model depth for the present problem are needed. Not every project requires a full whole-body model. A subsystem approach with realistic boundary conditions is often more precise (ore precise enough…) and efficient. Alternatively, dummy models can be more suitable when body’s internal mechanisms are not the focus and metrics (e.g., accelerations) are used directly for injury assessment. Robust, validated models are essential, along with a suitable level of detail and material cards matched to the load regime. Equally important is transparency: Which assumptions were made? Which parameters were sensitive? Which result ranges are realistic? Without this openness, results are hard to communicate and not reliable.

Applications differ in detail but not much in approach. In vehicle safety, the interaction of airbag, belt, seat, interior, and vehicle structure is tuned to reduce injury-relevant metrics as a system. In medical technology, implants and orthoses are designed to fulfill their function without unnecessarily loading surrounding tissue. In sports, the focus is on the interaction between athlete and equipment, sports gear, helmets, protectors as well as external protective elements like mats or barriers for understanding motion, identifying risks, and reducing injury potential through appropriate measures. In protective equipment development, helmets, vests, and armor are optimized in material, stack-up and geometry to prevent perforation and to minimize blunt trauma in non-perforation scenarios. Across all areas: Once the methodology is sufficiently validated, simulation enables extensive variant studies without costly, hazardous, or infeasible tests.

How to get Started with FE Analysis of Human Models

Start from load cases/scenarios and clarify which injury mechanisms are relevant. This defines the modeling strategy, from quick screening to a validated study. Where useful and feasible, always compare with experiments. Then run a focused sensitivity analysis on numerical drivers (mesh density, contact, material, damping) and experimental influences (geometry, speed, orientation). The goal is not to create a perfect replica of the real world, but rather a basis for decision-making: Which change delivers the greatest effect for reasonable effort and remains robust under variability?

A short note on the boundary conditions: Availability of human models varies widely. Some are open source, others licensed, not publicly available, or not approved for certain uses. It pays to clarify early what is permitted and which model variant best fits the application. Equally standard are data confidentiality and clear purpose limitation. Technology should serve an important goal what is more safety, fewer injuries. FiniteNow engineers can help you choose the right approach in a dedicated call.

In the end, dynamic structural simulation of the human body is comparable to simulation of other complex, highly nonlinear systems that we carry our frequently at FiniteNow. Those who model carefully, validate honestly, and interpret results clearly obtain reliable statements that support development across applications. Images and animations such as in the ball-on-chest example can illustrate findings. What matters, however, is the underlying basis: Assumptions, thresholds, sensitivities. Used correctly and carefully, the methodology answers the question that counts: Which specific change improves safety and by how much?

FiniteNow: Using our Digital Workflow for Quick Project Kick-offs and Robust Results

For requests such as an impact of an object on the thorax of a human body model, a clear, reproducible process and modelling strategy matters most. FiniteNow structures this process so that a precise question becomes a compact, well-defined simulation projectwith traceable assumptions and verifiable results. We want to take you through the digital instant quoting process to kick your simulaiton projects off wuickly, using the human simulaiton model as a reference.

It starts with a short briefing that is provided in an instant projecting work flow: what needs to be assessed; which data is relevant (e.g., rib strains, pressure levels in lung and heart, accelerations); which variants are necessary; and which human body model will be provided. The client may specify the solver (e.g., LS-DYNA), or FiniteNow will propose an appropriate solver for the task. On this basis, the scope is set: Is a thorax subsystem with realistic boundary conditions sufficient, or is a full-body model required – for example, if global kinematics or postural stability matter? The outcome is a precise proposal with defined cases and deliverables, ready to be ordered.

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World-class engineering simualtion with experienced consultants

Once the project is ordered, project execution and simulation model generation follows: positioning or morphing of the human model, gravity preloading, definition of contacts and boundary conditions, and setup of the agreed parameter cases (e.g., impact velocity, impact angle, impact location). Simulations are then executed and checked numerically, including energy-balance checks and contact behavior. The evaluation focuses on time histories and hot spots of the relevant quantities, revealing when critical states are reached, which structures are most loaded, and how variants change the outcome.

Results are consolidated in a short review. This session classifies the findings: which assumptions are sensitive, where statements are robust, and which changes have the greatest impact. Deliverables include animations and selected screenshots illustrating the event sequence, time-history plots, and a concise report summarizing assumptions, literature sources for thresholds, and key numerical checks. If desired, the screening study can transition directly into a follow-on project—for example, investigating protective equipment, material stack-ups, or geometry variants—using the same, already established evaluation methodology.

Added value through FiniteNow at a glance

• Immediate price indication & clear proposal: Early cost transparency and defined deliverables instead of open-ended estimates.
• Structured project flow: Fixed briefing, clear milestones, short reviews—less idle time and fewer misunderstandings.
• Up-front clarification of critical items: NDA, model rights/licenses, target metrics, variants, and reporting formats are resolved before any costs are incurred.
• Transparent assumptions & records: Documented sources, sensitivities, and parameter tables; results are shareable and auditable internally.
• Reusable setup: A consistent structure for input, evaluation, and reporting that simplifies follow-on studies and comparisons.
• Reliable communication: A single point of contact and a defined feedback cadence.
• Data and compliance security: NDAs, clear purpose limitation, and license checks for supplied models and data.

Thus, a concrete question – “Which injuries are expected under which conditions?”—becomes a well-structured project with transparent costs, a traceable approach, and robust results. Try it our yourself now: FiniteNow’s instant projecting platform for engineering simulation.