Analysis methods of the dynamic structural stress in a full-scale welded carbody for high-speed trains

Abstract

The calculation of the dynamic stress of a large and complex welded carbody is the key to the fatigue design and the durability evaluation of the carbody. Adopting the advanced structural stress based on the finite element method, a new finite element transformation method between random loads and dynamic stresses is proposed to be applied in carbody for high-speed trains. The multi-axial random dynamic load spectrums of full-scale carbody are obtained by the vehicle system dynamics method, and the shell finite element model of a full-scale carbody is established. Adopting the concept of a surrogate model, the finite element transformation relationship between the random load and the dynamic structural stress at concerned points is constructed by using multidisciplinary methods to compute the dynamic stress spectrums of concerned points at the welding seam, and dynamic structural stresses are compared and validated through carbody rig-test. The analysis methods of dynamic structural stress are performed systematically for a full-scale welded structure, which provides reference methods for the fatigue durability evaluation of large-scale welded structures.

Numerical simulation of large-scale structural systems

“…The high-speed EMU trains adopt a lightweight design and power distributed technology. In an article by Lu et al, 13 ''Analysis methods of the dynamic structural stress in a full-scale welded carbody for highspeed trains,'' the authors proposed a new shell finite element transformation method between random loads and dynamic stresses. The multi-axial random dynamic load spectra of full-scale carbody are obtained by the vehicle system dynamics method.…”

Fatigue life analysis of welded joints in the frequency plane in a structure designed for the defense industry

“…By making selections for the welded joint designed from these tables, the S-N curve is defined and fatigue life estimates are made [20]. While evaluating the spectral analyses of the welded joint region, stress values can be determined using IIW approaches [21,22]. In addition, for structures with small thicknesses such as the automotive sector, evaluations can be made with methods such as BS7608 and Volvo method [23].…”