Influence of Tensile Speeds on the Failure Loads of the DP590 Spot Weld under Various Combined Loading Conditions

Jung Han Song,Hoon Huh

doi:10.1155/2015/297915

Abstract

This paper is concerned with the evaluation of the dynamic failure load of the spot weld under combined axial and shear loading conditions. The testing fixture is designed to impose the combined axial and shear load on the spot weld. Using the proposed testing fixtures and specimens, quasi-static and dynamic failure tests of the spot weld are conducted with seven different combined loading conditions. The failure load and failure behavior of the spot weld are investigated with different loading conditions. Effect of tensile speeds on the failure load of the spot weld, which is critical for structural crashworthiness, is also examined based on the experimental data. The failure loads measured from the experiment are decomposed into the two components along the axial and shear directions and failure contours are plotted with different loading speeds. Dynamic sensitivities of failure loads with various combined loading conditions were also analyzed. Experimental results indicate that the failure contour is expanded with increasing loading speeds and failure loads show similar dynamic sensitivity with respect to the loading angles.

Highlights

Increasing concern of environmental safety and reduction of fuel consumption motivates car manufacturers to use lightweight materials having a higher tensile strength coupled with better ductility
Considering the safety standards required in the automobile industry, dual phase (DP) steel has gained its popularity as this steel has a higher tensile strength in conjunction with higher elongation compared to the steel grades of similar yield strength [1]
Dynamic failure tests of the spot weld are conducted with seven different combined loading conditions at various tensile speeds from quasi-static to 1.2 m/s

Summary

Introduction

Increasing concern of environmental safety and reduction of fuel consumption motivates car manufacturers to use lightweight materials having a higher tensile strength coupled with better ductility. Investigated dynamic failure loads of spot-welded lap-shear specimens using a Charpy impact test. Their experimental results revealed that the dynamic failure load of spot welds increases relative to the quasi-static failure load. Investigate the impact performance of spot welds in advanced high strength steels [11] It is, not feasible to perform dynamic lap-shear, cross-tension, and coach-peel tests for constructing a strain-rate dependent failure criterion that describes the behavior of spot welds under impact loading conditions because spot welds in automotive components are subjected to complicated dynamic loading conditions when they undergo crashed deformation [12]. Dynamic failure tests of the spot weld are conducted with seven different combined loading conditions at various tensile speeds from quasi-static to 1.2 m/s. Dynamic effects on the failure load of the spot weld, which is critical for structural crashworthiness, are examined based on the experimental data

Dynamic Failure Tests of a Spot Weld under Combined Loading Conditions

Evaluation of Dynamic Effect on the Failure Load of a Spot Weld

Conclusion

Conflict of Interests