SOLIDWORKS FEA Dilemma: SOLID or SHELL Element?

In Simulation by Genily Liang

Solid element or Shell element?

This is one of the most frequently asked questions when using SOLIDWORKS Simulation in FEA analysis works. This article provides comparison on some of the key specifications of SOLIDWORKS Simulation. 

We will look at a case study and investigate the differences in Solid and Shell element based on below expect.

  1. Preparation times
  2. Meshing and Solution times
  3. Result deviation
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Preparation times

SOLID Element

Shell Element

Relatively Short

Relatively Long

-       Simulation can start without much model preparation

-       Model preparations require; converting model to shell element.

-       Fixture, contact and loading can be assigned on ANY model entities (faces, edges or vertexs).

-       Fixture, contact and loading can be assigned to model entities of assigned shell (Faces, edges or vertexs) ONLY.

Meshing Time

Specifications

SOLID Element

Shell Element

Mesh type

Solid Mesh

Shell Mesh

Element size

37.455 mm

37.455 mm

Tolerance

1.87275 mm

1.87275 mm

Mesh quality

High

High

Total nodes

36486

10644

Total elements

17492

4824

Time to complete mesh

7 sec

2 sec

Solution Time

Specifications

SOLID Element

Shell Element

Total DOF

109704

64248

Time to complete mesh

1 min 26 sec

29 sec

Result Deviation

Specifications

SOLID Element

Shell Element

Max Displacement

25.472 mm

29.112 mm

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Comparing from the 3 expects of preparation, computation and result, there are pros and cons with SOLID and SHELL element approach.

SOLID element approach have shorter setup time as there is not much model preparation works involve and you can readily assign the constraint and contact sets directly on the model without the concern of “Model unstable” error message during computation. In this case, more computer resources are required from the indicator of higher number of DOF and calculation time.

On the other hand, Shell element approach might require a longer setup time as converting of solid entities into surface shell entities actions required. SOLIDWORKS introduce “Shell Manager” feature to help in speeding up the shell assignment task. Constrain and contact sets can only assigned to shell entities. User might find this time consuming when the assembly models become complicated. However, the calculation time is relatively faster while maintaining a certain tolerance in the result difference.

In short.

If you have adequate computer resources, relatively low iteration of changes in your model design, opt for SOLID element approach.

If you have limited computer resources, relatively high iteration of changes in your model design, opt for SHELL element approach, as in long term, you can benefits from having a large set of results data from a wide range of model design parameter changes in the shortest time.