Engineering and tested with automatic mesh generation for

Engineering analyses in CAD or integrated Computer Aided Engineering (CAE) tools,
are analytical where experiments are simulated through software 3.
Computational mechanics is one of the earliest CAE applications and applies
mechanics, mathematics, and numerical methods to simulate the physical behavior
of engineering artifacts 35. CAD workstations visualize large amounts of data and
complex analyses for efficient interpretation 3. 3D CAD models are analyzed
through integrated CAE tools including finite element stress distributions, simulated
automobile crash testing, and digital human modeling 2,3,5,8. Solidworks RKS
2017, CATIA V5, NX 10, Autodesk Fusion 360, and Autodesk AutoCAD offer a variety
of CAE/CAM capabilities including structure, static stress, fluid, thermal dissipation,
dynamic response, parametric optimization, and digital human
modeling/ergonomics analyses 15 -34.

Engineering analyses in CAD or integrated CAE tools are analytical where
experiments are simulated through software 3. Simulation is used for design
verification and performance optimization including the crashworthiness of vehicles
8. Experimental testing of physical prototypes is primarily used to assess material
properties and validate design performance, and is especially useful when analytical
models are not possible 3. Conventional design testing often involves post-
manufacturing quantification and late-stage physical prototypes while CAD/CAE
allows testing to be done throughout the design process and supports
multidisciplinary design analyses 2,3,8,10,40,42.

Finite element models (FEM)/finite element analysis (FEA), solid models, and
computer simulations are some of the most popular forms of engineering analyses
in design 6,42. Finite element modeling has been used in many engineering fields
to solve complex analyses by dissolving models into constituent problems that are
readily solvable 3,8,10. Finite element models are also frequently used to cross
check experimental results and identify necessary modifications 3. Finite element
analysis (FEA) performs stress, strain, and heat transfer calculations by
disassembling complex objects into basic components that are easier to solve; a
mesh of constituent components 2,3,6,7,8. 3D CAD solid and surface models allow
FEA meshes to be readily implemented and tested with automatic mesh generation
for CAD models, introducing analyses earlier in the design process 8. FEMs allow
engineers to modify designs and analyze their performance with lower time and
cost investments 6. FEA can be used to analyze a wide variety of physical
behaviors including stress, strain, temperature distribution, fluid flow, and
electric/magnetic fields 7,8,35.

Assumptions and material properties should be well understood when using
FEA/FEM. Results and assumptions must be evaluated by the user; CAD or FEA
software cannot tell whether mesh density, element type, and material assumptions
are appropriate 8. Other determinants of FEA quality include material elasticity,
element shape, stress and temperature coupling, and mesh quality 8.

Literature also suggests validating CAD files before releasing them for analysis and
manufacturing 40. For example, it was found that finite element analysis (FEA)
users spend up to 70% of their time fixing invalidated CAD models, and CAD model
validation reduced model rework time 50 – 80% 40. Other research suggests that
FEA experts sometimes spend days importing CAD files into FEA pre-processing
programs that heal model geometry and generate structure meshes 44.

FEA can further improve design quality when combined with optimization by
reducing part material up to 82% to produce products with less waste 3,7. There
are often several, if not thousands of acceptable solutions to a design problem and
engineers wish to find the best of these solutions using optimization 35.