Simplifying FEA for Design Engineers with CAD-Integrated Linear Static Analysis

CAD-integrated simulation is not a new idea. In fact, a well-integrated simulation solution has been decades in the making. Yet, the widespread adoption of simulation tools by design engineers remains a persistent challenge.

The principle problem has historically centered on the disconnect between the complexity of the simulation setup and the accessibility for the average engineer. The level of specialized expertise required to correctly define the boundary conditions, apply loads, mesh the geometry, and interpret the results was still too high, making advanced simulation inaccessible for many engineers who could benefit most from its insights during the critical design phase.

This steep learning curve often relegated simulation to a small group of highly trained analysts, creating bottlenecks in the product development lifecycle and delaying crucial design validation until late-stage prototyping.

The goal of true CAD-integrated simulation is to lower this barrier, enabling engineers to perform “what-if” analyses earlier and more frequently without requiring deep finite element analysis (FEA) expertise.

Linear Static Analysis: Simplified Setup

Onshape's current simulation capabilities are strategically focused on addressing the most prevalent requirements in structural engineering analysis.

These core functions are currently centered on Linear Static Analysis. This methodology represents the most fundamental and widely used form of structural simulation in engineering. Its core purpose is to precisely determine how a single part, a complex assembly, or a larger structure will react and perform when subjected to external forces, pressures, or loads.

The defining characteristic of Linear Static Analysis is the assumption of static loading. This means the applied loads are constant in magnitude and direction and do not change with time. They are non-transient, and any dynamic or inertial effects are considered negligible and therefore excluded from the calculation.

Further, this analysis is linear, which requires two primary conditions to be met:

• Material Linearity: The material of the component must behave in a linearly elastic manner. This means that stress is directly proportional to strain (Hooke's Law), and the material will fully return to its original shape once the load is removed (no plastic deformation).
• Geometric Linearity (Small Deflection): The resulting displacements and deformations of the structure must be small relative to the overall dimensions of the part. This allows the equilibrium equations to be formulated based on the original, undeformed geometry, simplifying the mathematical model significantly.

Linear Static Analysis: Key Results

Linear Static Analysis provides critical insights into several key engineering metrics, including:

• Stress Distribution: Identifying the location and magnitude of internal stresses is essential for predicting potential failure points due to material yield or ultimate strength. Von Mises Stress, Signed Von Mises Stress, and Principal Stresses can be plotted in Onshape.
• Displacement: Determining how far the structure moves from its original position under load, which is critical for meeting clearance requirements and performance specifications.
• Factor of Safety: Quantifying the robustness of the design by comparing the maximum calculated stress to the material's allowable stress limits.

In essence, it provides a crucial and reliable baseline assessment of a design's structural integrity under its intended, steady-state operational conditions.

Simulation Visualization: Interactive and Intuitive

Onshape's results visualization provides engineers and product designers with fast, clear, actionable insights from simulations without complex finite element analysis (FEA) post-processing.

Onshape translates complex numerical data into meaningful visual feedback – like stress contours and heatmaps – that directly inform design decisions. This empowers designers to perform verification and optimization within their workflow, making simulation an intrinsic part of a rapid, iterative design process.

• Real-Time Deformation: You can animate the deformation scale to intuitively understand how the structure is bending or twisting.
• Color Plots: Toggle quickly between a variety of Stress metric, Displacement, and Factor of Safety. The legends are dynamic, allowing you to drag the upper and lower limits to highlight specific areas of concern (e.g., "see all areas with a Safety Factor below 2.0").
• Connection Visualization: A dedicated visualization mode allows you to see exactly how the solver interprets your assembly mates, showing rigid bonds in one color and moving degrees of freedom in another.

Cloud-Native Simulations: The "Zero-Install" Advantage

The most immediate difference with Onshape Simulation is where it lives: in your browser. Because Onshape is built on a cloud-native architecture, there is no separate simulation "module" to download, install, or license separately.

In traditional workflows, the simulation model is a copy of the design model. If the design changes, the simulation is instantly obsolete. In Onshape, the simulation is a feature of the assembly itself. There is no file translation or export. When you modify a part in a Part Studio, the assembly updates, and the simulation results are refreshed immediately. Designers now have instant feedback, and there’s no version confusion.

The cloud-native architecture also gives designers:

• Scalable Compute: Heavy calculations are offloaded to cloud servers, not your local machine.
• Design History: The entire history of your design change is captured. You can always go back to check how the current design performs in relation to previous designs.