Welding is the main method of joining plate steel. Its use leads to significant residual welding stresses. Residual stress can significantly affect the load-bearing capacity of long-span steel bridges. In this work, a finite element calculation of residual welding stresses of steel sheets up to 100 mm thick was carried out, and the distribution of surface residual stresses and the influence of sheet thickness on the residual surface stress were identified.

Keywords: steel bridge, plate steel, welding residual stresses, finite element method, welded joint, stress distribution

The thickness of the steel sheets used in the element was gradually increased to meet the load bearing capacity requirements of large span steel bridges. As the main method of joining heavy plate steel, welding results in significant residual welding stresses with a complex distribution. Large residual stress during welding will significantly affect the performance of steel bridges. In this work, the distribution of residual stress in a welded thick steel sheet is systematically investigated, a specimen with a thickness of 80 mm was designed and manufactured, and the residual stress of welding was measured by X-ray diffraction.

Keywords: steel bridge, thick steel plate, welding residual stresses, X-ray diffraction method, weld joint

The study of the problem of fretting damage to a mechanical assembly bolted in three dimensions requires the analysis of stress fields in Cartesian coordinates along the angle and radius of contact pads. It also requires determining the location of the crack initiation and propagation. In this study, we will focus on numerical simulation using ANSYS. The results obtained in the form of nodal solutions show in detail the positions of stress concentrations and the formation of the bolted assembly. The contact surface between plates (or contact elements) is characterized by contact pressure, adhesion and clearance. The results obtained made it possible to determine the stress that caused the initiation and propagation of a crack, as well as the position of the damaged area by fretting.

Keywords: bolt assembly, contact modeling, damage zone, fretting, Ramberg-Osgood law, Von Mises stresses

Flexible structures typically have low flexible stiffness and a low material damping factor. Mild excitation can result in damaging high amplitude vibration and long recovery times. This can lead to fatigue, instability and poor performance. Vibration control of flexible structures is an important issue in many engineering applications, especially for precise performance in aerospace systems, satellites, flexible arms, etc.

Keywords: natural frequency, flexible stiffness, vibration, Langrange's equation, Euler's method, damping force, beam theory

The use of corrugated metal sheet roofing is on large scale in rural as well as urban regions of India. Most of the market consumed by the corrugated metal sheet roofing is residential building constructions. As concerned with the safety and the reliability of the corrugated metal against all the impact loads and energy level, the material needs to be tested under certain energy levels. So as to attain the safety parameters against all set of conditions. It is high time to analyse the corrugated metal sheet roofing on impact load and energy levels for building material, for sustainable and material selection.

Keywords: GL, failure theory, energy absorption, strain energy, principal stress theory, maximum shear stress theory, maximum deformation theory, shock stress, corrugated board, metal sheet