Investigation of the Strength of H440 Graphite When Subjected to Combined Primary and Secondary Stress

摘要

An experimental and analytical investigation of the strength of a fine-grained graphite, H440, under combined mechanical and thermal stress is described. Small sample laboratory tests were carried out to establish a mechanical property data base from which statistical parameters could be determined and then used in finite element codes for predicting failure probabilities of large graphite structural components under load. The theory was applied to graphite rings under an imposed thermal stress from a heat flux applied to the inner surface of the rings and under mechanical stress caused by diametrically opposed concentrated loads applied to the outer surface of the rings. Rings of H440 graphite were fabricated in two sizes and tested to the combined thermal and mechanical loadings. From the results of theory and the experiments, a design rule for combining mechanical and thermal stress in graphite structural components is proposed.