Papers by Keyword: Fatigue Design Criterion

Abstract: In order to develop a fatigue design method for the actual railroad car body structures using the fatigue data on simulated single spot welded lap joints, firstly, evaluated fatigue strength on the spot welded t-type member which is a component of the actual railroad car body structure. And next, possibility of fatigue design for spot welded T-type member using the fatigue data of single spot welded lap joints was investigated. From the results, it was found that, even though there is some difference in fatigue strength between single spot welded joint and the actual members under the same fatigue life, the fatigue design criterion could be predicted by correction between them.

Abstract: The suspension system of vehicle is directly influenced to ride and handling. Therefore, suspension part should have enough endurance during its lifetime to protect passenger. Spring is one of major suspension part of vehicle. Thus, in this paper, a fatigue design method for leaf spring based on proving ground response was proposed. At first, stress and displacement of leaf spring are measured through the proving ground test. And next, the maximum load acting on leaf spring assembly under driving condition was defined from the road load response. On the base of these results, fatigue tests for leaf spring assembly and 3-point bending fatigue tests for material of leaf spring were carried out. From the above, the maximum load-fatigue life relation of leaf spring material and assembly was defined, and 3-point bending test result has good agreement with leaf spring assembly fatigue test result. Thus, it is expect that economical fatigue design criterion for leaf spring assembly can be determined from fatigue data of simple smooth specimen by 3 point bending fatigue tests.