Abstract
The paper presents an approach to optimal design of a frame of an off-road truck. The objective is to minimize the weight of an existing frame. The requirement imposed is that the stiffness of the frame remains approximately the same while the cross-sectional and geometrical parameters may be varied in some specified range in order to minimize the weight. Multiple load cases are taken into account simultaneously in order to consider different loading situations. The design problem is formulated in a form of a standard problem of mathematical programming. This problem is then solved by using a gradient-based approximation method. The frame of the truck is discretized by employing highly accurate beam finite elements.