Overview
We have a number of Mechanical/Naval Engineers using Structural 3D. A lot of the benefit is using it as a complimentary to traditional CAD/FEA to run simple frame analysis, that help shape the initial design. We decided to run a test to analyse the performance of Structural 3D vs traditional CAD/FEA software.
The structure chosen was a hydraulic frame used in a maritime application. It was a fairly simple 21 member structure that featured a pinned circular rod. To simplify this, the entire model was decided to contain single section properties.
Experiment Conditions
| Item | SkyCiv | CAD/FEA Analysis |
|---|---|---|
| Operating System | I7-6700 @2.6GHz - Mozilla FireFox | I7-6700 @2.6GHz |
| User Proficiency | Intermediate | Intermediate |
| Analysis Type | 1D Elements (Linear Static) | 3D FEA using ANSYS |
| Software | SkyCiv Structural 3D | Solid Works / ANSYS |
| Mesh Coarseness | Medium (25 eval points) | ANSYS Default Meshing Setting |
Time:
| Item | SkyCiv | CAD/FEA Analysis |
|---|---|---|
| Software Loadup | 1 minute | 5 minutes |
| Modelling | 12 minutes | 120 minutes |
| Meshing | 0 minutes | 15 minutes |
| Applying Loads | <1 minute | 3 minutes |
| Solving Time | <1 minute | <1 minute |
| Total | 0.25 hours (15 minutes) | 2.4 hours (144 minutes) |
Analysis Comparison
It was always going to be interesting to compare the results of the analysis - particularly as we are comparing apples with oranges. We are comparing the analysis of a simplified linear model VS a 3D model of joints, members and meshes. But obviously we want to make sure there is some degree of accuracy between the two methods. We found that the software results were within 7.4% of each other for peak deflection.
1.1446mm1.0602mm
Deflection Results
SkyCivCAD/FEA
1.1446mm1.0602mm
Summary
You could conclude that when looking at a frame analysis, the linear analysis software could produce results within an 8% tolerance of FEA software. This result took one-tenth the time to model, mesh and analyse. Two courses of action could be recommended:
- Simplified Linear FEA took one-tenth the time to model and analyze
- Results were within 7.4% accuracy
- Use Linear software in place of CAD/FEA for these sorts of frames. Knowing that results will be within 8% accuracy (linear analysis is typically overstated)
- Use Linear software to come up with preliminary designs or double checks. Then finalize design using CAD/FEA models
Sam Carigliano
CEO and Co-Founder of SkyCiv
BEng (Civil), BCom
LinkedIn
CEO and Co-Founder of SkyCiv
BEng (Civil), BCom