From numerical calculations to materials testing homologation: a biaxial fatigue reliability prediction methodology for structural components

Abstract

This article investigates a fatigue approach conducted from the design phase to testing approval. It considerers modern analytical and experimental tools for structural durability assessment over each development phase for two reference components aiming an early approval methodology validation for a new design. A Finite element analysis procedure was used to set critical spots for measurements minimizing the data acquisition efforts. Based on measured data, strain life calculation was done for two reference components in order to set the release goals for a new design submitted to this approach. An innovative fatigue experimental technique is proposed using component extracted specimens and an edited input cycle loads. Considering the random data from a standard test track and signal proportionality evaluation, while assuming the Brown Miller equation for bi-axial fatigue together with Ramberg-Osgood model, equivalent damage load blocks were edited and used as input for durability assessment on specimens representing the component material. The results for the three parts materials were plotted as Weibull diagram for B10 life estimation. Fatigue life results showed good correlation with the reference parts structural performance thus validating the method as well as approving the new design for production without additional on-vehicle durability testing. The methodology and the fatigue testing proposal is therefore recommended for future applications on similar developments.

Influence of tire sizes over automobile body spectrum loads and fatigue damage accumulation

“…It would also be worthwhile to crosscheck the present results with analytical or numerical models, to investigate the influence of tire stiffness and mass upon the developed structural vibration modes. Spinelli et al [19] recently discussed the interplay between finite element modeling and physical tests for vehicle project validation. Also, a classification of the load events as the one recently introduced by Yunoh et al [20] could be attempted.…”

Structural safety evaluation of a subway bolster based on numerical simulation and experimental test

“…The Swing Motion Bogie with sufficient fatigue strength can be used up to the endurance life of a freight car, and the maximum stress in bolster area is Von-Mises stress on side frame [14]. Additionally, the biaxial fatigue reliability prediction methodology and some fatigue safety life assessment research related to large complex structural parts, like the aircraft engine support structure, can also be used as references in the structural safety evaluation of the bolster in the near future [15,16].…”

Development of a material testing machine with multi-dimensional loading capability

“…Research on multi-axial loading equipment has been recently reported, including biaxial tension and compression tests (Zhang and Zhang, 2013;Smoger et al, 2012;O'Connell et al, 2012, biaxial fatigue tests (Spinelli et al, 2013), triaxial tension and compression test (Feng et al, 2010;Lee et al, 2013;Soroush and Jannatiaghdam, 2012;Cil and Alshibli, 2014). Most of the mentioned biaxial and triaxial material tests are based on the composing of orthogonal uniaxial load cell actuated by hydraulic or electric motors.…”