126x
009018
2020-07-26

VE 0018 | Plastic Bending – Tapered Cantilever

Description

A tapered cantilever is fully fixed on the left end and subjected to a continuous load q. Small deformations are considered and the self-weight is neglected in this example. The problem is described by the following set of parameters. Determine the maximum deflection uz,max.

Material Elastic-Plastic Modulus of Elasticity E 210000.000 MPa
Poisson's Ratio ν 0.000 -
Shear Modulus G 105000.000 MPa
Yield Strength fy 40.000 MPa
Geometry Cantilever Length L 4.000 m
Width w 0.005 m
Left Side Height h1 0.250 m
Right Side Height h2 0.150 m
Load Continuous Load q 2300.000 N/m

Analytical Solution

This is more complex variant of the verification example 17. The tapered cantilever is considered in this case. The continuous load q causes the elastic-plastic state of the plate. The calculation procedure is similar to verification example 17.

The elastic-plastic moment Mep (internal force) has to equal to the bending moment M (external force). The curvature κp in the elastic-plastic zone results from this equality.

The total deflection of the structure is defined as a superposition of the elastic-plastic and the elastic contribution using the Mohr's integral.

RFEM Settings

  • Modeled in RFEM 5.26 and RFEM 6.02
  • The element size is lFE=0.020 m for files 0018.01-0018.03 and lFE=0.005 m for files 0018.04-0018.05
  • Geometrically linear analysis is considered
  • The number of increments is 10
  • Shear stiffness of the members is neglected

Results

Model Analytical Solution RFEM 5 RFEM 6
uz,max [mm] uz,max [mm] Ratio [-] uz,max [mm] Ratio [-]
Isotropic Plastic 1D 85.999 86.215 1.003 86.139 1.002
Isotropic Nonlinear Elastic 2D, Plate 86.566 1.007 86.431 1.005
Isotropic Plastic 2D/3D, Plate 84.142 0.978 84.142 0.978
Isotropic Nonlinear Elastic 2D, Plate, Variable Thickness 83.728 0.974 83.121 0.967
Isotropic Plastic 2D/3D, Plate, Variable Thickness 83.088 0.966 83.088 0.966
Isotropic Nonlinear Elastic 1D 86.215 1.003 86.136 1.002

References
  1. Lubliner, J. (1990). Plasticity Theory. New York: Macmillan.