SHAPE OPTIMIZATION OF OPENINGS IN COMPOSITE PRESSURE-VESSELS

To be of any practical use, a pressure vessel must contain openings through which the contents of the vessel may be accessed. It is desired to determine the optimum shape of a hole to be found on the surface of a cylindrical composite pressure vessel subjected to internal pressure and torsion loads in order to reduce the stresses found around these holes. Two materials with quite different physical characteristics, as well as five different layups of the materials, are used in the investigation. The fracture criterion to determine failure around the hole is the Tsai-Hill combined stress factor used in conjunction with the point stress criterion. The OASIS-ALADDIN optimization system, developed at The Royal Institute of Technology, is used to perform the optimization and analyze the results. Results show that the optimum hole shapes are only slightly affected by material properties and laminate geometry.