VM-EXD-MECH-005

VM-EXD-MECH-005
3-D Tension Failure Test (Cubes)

Overview

Reference:Material Data Values
Analysis Type(s):Explicit Dynamics 3-D
Elements:

8-Node Linear Interpolated Reduced Integration Hex

ANP Tet

Boundary Conditions:Fixed Constraint, Velocity (Constant)
Structural Interactions:No
Fluid-Structure Interactions:No
Bonds:No
Materials:Steel 4340

Test Case

This problem tests the tensile pressure failure, plastic strain failure, principal stress failure, and principle strain failure of 8-node linear interpolated reduced integration hexagonal elements, and average nodal pressure tetrahedral elements subjected to pure tension.

Calculation Description

Eight parts are created, each representing a 1 m cube:

Figure 234: Finite Element Model of Eight Steel Cubes

Finite Element Model of Eight Steel Cubes

Four parts are meshed with a single hex element. The other four parts are meshed with four ANP Tet elements.

The four hex-part/tet-part pairs are each assigned a different material.

All four materials use Steel 4340 obtained from the Explicit Materials data source in Engineering Data, but with different failure criteria. From top to bottom, the failure criteria are:

  • Tensile pressure failure at a maximum tensile pressure = -3E+10 Pa

  • Plastic strain failure at strain = 0.15

  • Principal stress failure at a maximum principal stress = 3E+10 Pa

  • Principal strain failure at a maximum principal strain = 0.15

The left boundary of each cube has a fixed constraint. A constant x velocity of 100 m/s is applied to the right boundary of each cube.

Result probes for pressure, effective plastic strain, principal stress, and principal strain are defined for the four pairs of cubes from top to bottom, respectively.

The calculation is run with a fixed time step of 5E-6 s-6 for 1000 cycles.

Calculation Results

The following plots show pressure, effective plastic strain, principal stress, and principal strain vs. time for the pairs of cubes from top to bottom. In all cases, the failure points correspond to the defined failure limits.

Figure 235: Pressure Over Time

Pressure Over Time

Figure 236: Effective Plastic Strain Over Time

Effective Plastic Strain Over Time

Figure 237: Principal Stress Over Time

Principal Stress Over Time

Figure 238: Principal Strain Over Time

Principal Strain Over Time