Our website uses cookies. By using the website you agree ot its use. More information can be found in our privacy policy.

Problem Description

Reliability Based Design Optimization (RBDO) includes uncertainties of design variables in the optimization.



The example demonstrates:

  • Reliability Based Design Optimization (RBDO)
  • Creating statistical distributions and assigning them to design variables
  • Probabilistic constraints


Problem Description

The problem is of a simple two-bar truss. It has two variables: the crosssection area of the bars (Area) and the leg width (Base). Both the thickness and the leg width have uncertainties associated with them. A value of the Base variable and the Area variable must be obtained that minimizes mass while respecting a probability of not exceeding the allowable stress value.


Design Formulation

The design formulation is as follows:

  • Minimize the weight of the structure subject to the probability of the maximum stress in the bars exceeding the failure stress is limited.


Problem Solution