Optimization of composite carriage for a coordinate measurement machine

The growing need for high quality and reliability of products requires the control of the accuracy of dimensions and shape of product components. Coordinate Measurement Machines (CMM) are now able to measure the dimensions and/or the shape of objects with submicron precision. The desire for high-speed measurement, has stimulated the interest of CMM manufacturers in the use of composite materials for the structure of their machines. Composites are lighter than conventional materials, and are generally less affected by temperature changes.

In cooperation with one of the major European CMM manufacturers, the problem of redesigning a steel carriage of a CMM, from composite materials component is considered. A simple strength-of-materials based calculation is used to design a prototype of the carriage, which is built and mounted on the machine to be tested.

A NASTRAN finite element model of the composite component is created to analyze more accurately the behavior of the composite structure. Structural optimization is next performed to seek minimum weight and maximum stiffness designs of the structural component.