# Distribution of Mechanical Properties of Steel Along the Curvature of Corrugated Web SIN Girders

## TL;DR

This study examines how the mechanical properties of steel vary along the curved sections of corrugated web SIN girders and how this affects structural stability.

## Contribution

The paper introduces a statistical analysis of steel strength parameters in corrugated webs, revealing how their variation impacts structural failure initiation.

## Key findings

- Mechanical properties of steel differ between flat and curved sections of corrugated webs.
- Residual stresses and deformations were determined through metallographic and hardness tests.
- Stability loss initiation occurs in flat web sections, influenced by yield strength and geometry.

## Abstract

What are the main findings?
The study presents the results of statistical investigations into random strength parameters of steel used in manufacturing of corrugated webs for SIN plate girders, depending on the place of the specimen cut-out, that is, from the flat section or ridge of the wave. Metallographic and Vickers hardness tests were performed. Differentiation of mechanical properties was confirmed. Values of deformations and residual stresses were determined.

The study presents the results of statistical investigations into random strength parameters of steel used in manufacturing of corrugated webs for SIN plate girders, depending on the place of the specimen cut-out, that is, from the flat section or ridge of the wave. Metallographic and Vickers hardness tests were performed. Differentiation of mechanical properties was confirmed. Values of deformations and residual stresses were determined.

What are the implications of the main findings?
The performed tests demonstrated close relationships between the effects of web metal and strength parameters along the web curvature on the beginning of the failure phase of the corrugated web while buckling was initiated. Such conclusions are made which can be useful for design purposes.This provides insights for future research on sinusoidal web stability.

The performed tests demonstrated close relationships between the effects of web metal and strength parameters along the web curvature on the beginning of the failure phase of the corrugated web while buckling was initiated. Such conclusions are made which can be useful for design purposes.

This provides insights for future research on sinusoidal web stability.

This paper presents results from statistical tests on random parameters of strength properties of steel used to manufacture corrugated webs for SIN plate girders, depending on the place of specimen cut-out, that is, from the flat section or ridge of the wave. The tests were performed on specimens collected from 12 randomly selected corrugated sheets with thicknesses of 2, 2.5 and 3 mm, provided by the manufacturer of SIN beams. The analysis was used to select variation coefficients of yield strength VRe = D(Re)/E(Re) and partial coefficients of yield strength γm for steel in flat and arched parts of the web. Metallographic and Vickers hardness tests were performed. Values of deformations and residual stresses were determined. The close correlation between the influence of the web plate shape and the strength parameters along the web curvature was demonstrated. Analysis of the initiation points of stability loss (IPLS points) revealed that the initiation of stability loss occurs in the area of the flat web sections. In addition to the influence of geometry, the influence of the change in yield strength, as identified in this paper, can be observed. Consideration of random features of yield strength and web thickness can lead to modifications in designing and calculating structures made of SIN girders.