Numerical and experimental investigation on multiaxial fatigue damage estimation of Qualmark chamber test table structures under random vibrations

Abstract

The aim of this paper is to determine the fatigue damage of structures subject to random vibrations generated by Qualmark chamber. In real life, structures are generally subjected to complex multiaxial random load. To determine their fatigue life, many criteria have been elaborated, mostly in time domain. To minimize the computing time, the fatigue damage analysis should be done in the frequency domain. Tests that lead to the failure of the structures are commonly used to determine their weakness. But these tests are sometimes costly. To this end, in this paper an original new numerical model of the Qualmark chamber that leads us to determine the generated excitation at each point of its table is proposed. This model is validated using experimental measurement where adjustment process is proposed. Then, we develop a numerical strategy that leads to determine the multiaxial fatigue damage of structure under random vibrations using Matsubara’s criterion developed in the frequency domain of structures tested with Qualmark chamber. A numerical application of a PCB tested with Qualmark chamber is presented at the end of this paper where fatigue damage is determined at each point using the developed strategy. Boundaries condition of the PCB is then determined using the proposed Qualmark table model.

Keywords:

• Random vibrations
• power spectral density
• fatigue damage
• Matsubara’s criterion
• Qualmark chamber
• reliability test

Acknowledgment

The authors gratefully acknowledge the support and the contribution of DGA and all companies in this project, specifically THALES France, CEVAA France and MB Electronic France companies.

Additional information

Funding

The present research work is a part of PISTIS Project, financed by DGA France (Postdoc position).