Staged analysis with plasticity: yielding only in the body born later
Birth and death of elements (staged analysis)PASS · <0.01%Two cubes are stacked; the elastic body A (σy = 300 MPa) exists from the start, the weaker elastic-plastic body B (σy = 150 MPa, linear isotropic hardening) is born on stage 2. The face pressure on B exists in the model from the start but acts on B only once B exists. Under uniaxial strain (rollers on the lateral faces) B yields and A stays elastic; the plastic strain and the displacements follow the closed form of J2 radial return. The born body starts with a clean plastic history.Two cubes are stacked; the elastic body A (σy = 300 MPa) exists from the start, the weaker elastic-plastic body B (σy = 150 MPa, linear isotropic hardening) is born on stage 2. The face pressure on B exists in the model from the start but acts on B only once B… show full text
- Tolerance:
- 5%
Problem statement
- Geometry
- Two cubes 100 mm stacked along z, P1 tetrahedra of size 25 mm in one conformal mesh; lateral faces on rollers (uniaxial strain), base face held in z.
- Material
- E = 210 GPa, ν = 0.3; body A: σy = 300 MPa, body B: σy = 150 MPa, tangent modulus Et = 1 GPa (H = 1.005 GPa); small-strain (material-only) nonlinearity.
- Boundary conditions
- Pressure 400 MPa on the top face of body B. Stage 1: body A only (the load acts on no active element). Stage 2: body B is born.
- Measured quantity
- Equivalent plastic strain of B (closed form), of A (0), and the vertical displacement of the tops of A and B.
WebCAE Terminal
Paste these commands into the Terminal panel inside WebCAE. They use the same text DSL as the application; run one command per line:
units mm
material E=210e9 nu=0.3 plasticity=j2 yield=300000000 hardening=linear et=1e9
primitive box dx=100 dy=100 dz=100
material E=210e9 nu=0.3 plasticity=j2 yield=150000000 hardening=linear et=1e9
primitive box dx=100 dy=100 dz=100 oz=100
mesh tet size=25 bonding=1 glue=full
fix surface number 5 component=z
fix surface number 1 component=x
fix surface number 2 component=x
fix surface number 27 component=x
fix surface number 28 component=x
fix surface number 3 component=y
fix surface number 4 component=y
fix surface number 29 component=y
fix surface number 30 component=y
load surface number 32 pressure=400000000
nlgeom material
stage add name=A_only
stage add name=cast_B activate=body2
solve static
stage view 1
probe plastic_strain at z=0 id="epA_1"
stage view 2
probe plastic_strain at z=0 id="epA_2"
probe plastic_strain at z=200 id="epB_2"
probe displacement_z at z=100 id="u100_2"
probe displacement_z at z=200 id="u200_2"Results comparison
| Reference value | εp(B) = 0.000520324εp(A) = 0u_z верха B = -0.312726 мм |
| Our result | εp(B) = 0.000520324εp(A) = 0u_z = -0.312726 мм |
| Deviation | <0.01% |
| Tolerance | 5% |
| Status | PASS · <0.01% |
| Mesh details | тет4 (P1), размер 125 мм (881 тетр.), сборка из склеенных тел; 2 стадий, 12 шагов, 15 итераций Ньютона; мягкость неактивных элементов 1e-6; 2.4 с на скрипт (сетка + расчёт) на нативе |
Updated: 2026-10-22 · WebCAE solver