VM-LSDYNA-SOLVE-026

VM-LSDYNA-SOLVE-026
Radial Displacement of a Pinched Cylinder

Overview

Reference:

Cook, R. D. (1981). Concepts and applications of finite element analysis. (2nd ed.). John Wiley and Sons. pp.284-287.

Takemoto, H. & Cook, R.D. (1973). Some modifications of an isoparametric shell element. International Journal for Numerical Methods in Engineering, 7 (3).

Analysis Type(s): Analysis Type
Element Type(s): Element Type
Input Files:Link to Input Files Download Page

Test Case

A thin-walled cylinder is pinched by a force F at the middle of the cylinder length, shown in Figure 98. Determine the radial displacement 𝛅 at the point where F is applied. The ends of the cylinder are free edges.

This problem is also presented in test case VM6 in the Mechanical APDL Verification Manual.

Figure 98: Problem Sketch: Pinched Cylinder

Problem Sketch: Pinched Cylinder

Material PropertiesGeometric PropertiesLoading

E = 1.05e7 psi

v = 0.3125

r = 4.953 in

t = 0.094 in

l = 10.35 in

F = 100 lb

Analysis Assumptions and Modeling Notes

A one-eighth symmetry model is used. One-fourth of the load is applied due to symmetry with card *LOAD_NODE_POINT. The thin-walled cylinder is modeled with shell element elform 2 and 16. An implicit analysis is performed to determine displacement where the load is applied.

The 1/8 thin-walled cylinder model mesh is shown in Figure 99.

Figure 99: 1/8 Thin-Walled Cylinder Mesh

1/8 Thin-Walled Cylinder Mesh

Results Comparison

ResultsTarget LS-DYNASolverError (%)
Deflection (in) elform = 2 0.11390.11581.67
Deflection (in) elform = 16 0.11390.11541.32

The deformed cylinder is shown in the following contour plot, Figure 100.

Figure 100: Deformed Thin-Wall Cylinder at End of Analysis (elform = 16)

Deformed Thin-Wall Cylinder at End of Analysis (elform = 16)