STRUCTURAL ANALYSIS TO IMPROVE THE PERFORMANCE OF A RETRACTABLE JOINTED-CRANE: FAILURE DUE TO OVERLOADING

Abstract

This paper proposes a numerical assessment of the after-test failure of a retractable jointed-crane by using finite element analysis (FEA). The original design of the equipment involves a jointed section of coplanar arms and a telescopic section of collinear arms, which complies with the prevalent design standard, applicable for this kind of machinery in Mexico. A prototype of this design was built and was damaged during a beta test, presumably due to a crane misuse. The suggested numerical analysis was carried out in a FEA commercial software by assembling the component by kinematic pairs method, and considering dynamic loads and their resulting reactions at each element. The numerically obtained failure in the components was compared with the observed damage which indicated a difference less than ten percent in the permanent deformation results. Some modifications are recommended on the damaged components to increase the minimum safety factor, reaching up to sixty percent increment in this performance parameter. The causes of the failure are discussed based on the numerical results, and operation recommendations are argued in order to avoid future complications.