Spot Weld Failure Loads under Combined Mode Loading Conditions

Author(s):  
S.-H. Lin ◽  
Jwo Pan ◽  
S. Wu ◽  
T. Tyan ◽  
P. Wung
2008 ◽  
Vol 22 (09n11) ◽  
pp. 1469-1474 ◽  
Author(s):  
JUNG-HAN SONG ◽  
HOON HUH ◽  
JI-HO LIM ◽  
SUNG-HO PARK

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 are 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. Dynamic effects on the failure load of the spot weld, which is critical for structural crashworthiness, are also examined based on the experimental data. In order to evaluate the effect of the strain rate on the failure contour of the spot weld under combined axial and shear loads, the failure loads measured from the experiment are decomposed into the two components along the axial and shear directions. Experimental results indicate that the failure contour is expanded with increasing strain rates according to the rate sensitivity of the ultimate stress for welded material.


2004 ◽  
Vol 44 (2) ◽  
pp. 147-157 ◽  
Author(s):  
S. -H. Lin ◽  
J. Pan ◽  
S. Wu ◽  
T. Tyan

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Jung Han Song ◽  
Hoon Huh

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.


2015 ◽  
Author(s):  
Sivaprasad Koralla ◽  
Ganesh Bhagwant Gadekar ◽  
V Ramana Pavan Nadella ◽  
Susanta Dey

Author(s):  
Keith Friedman ◽  
Khanh Bui ◽  
John Hutchinson

Vehicle door latch performance testing presently utilizes uniaxial quasi-static loading conditions. Current technology enables sophisticated virtual testing of a broad range of systems. Door latch failures have been observed in vehicles under a variety of conditions. Typically, these conditions involve multi-axis loading conditions. The loading conditions presented during rollovers on passenger vehicle side door latches have not been published. Rollover crash test results, rollover crashes, and physical Federal Motor Vehicle Safety Standard (FMVSS) 206 latch testing results are reviewed. The creation and validation of a passenger vehicle door latch model is described. The multi-axis loading conditions observed in virtual rollover testing at the latch location are characterized and applied to the virtual testing of a latch in the secondary latch position. The results are then compared with crash test and real world rollover results for the same latch. The results indicate that a door latch that meets the secondary latch position requirements may fail at loads substantially below the FMVSS 206 uniaxial failure loads. In the side impact mode, risks associated with door handle designs and the potential for inertial release can be considered prior to manufacturing with virtual testing. An example case showing the effects of material and spring selection illustrates the potential issues that can be detected in advance of manufacturing. The findings suggest the need for re-examining the relevance of existing door latch testing practices in light of the prevalence of rollover impacts and other impact conditions in today's vehicle fleet environment.


2008 ◽  
Vol 22 (31n32) ◽  
pp. 5527-5532 ◽  
Author(s):  
J. H. SONG ◽  
J. W. HA ◽  
H. HUH ◽  
J. H. LIM ◽  
S. H. PARK

This paper is concerned with the evaluation of the dynamic failure load in the lap-shear tests of a spot weld. Dynamic lap-shear tests of a spot weld in SPRC340R were conducted with different tensile speeds ranging from 5×10-5 m/sec to 5.0 m/sec. Dynamic effects on the failure load of a spot weld are examined based on the experimental data. Experimental results indicate that failure strength increases with increasing loading rates. Finite element analyses of dynamic lap-shear tests were also performed considering the failure of a spot weld. A spot weld is modeled with a beam element and dynamic failure model is utilized in order to describe the failure of a spot weld in the simulation. The failure loads obtained from the analyses are compared to those from the lap-shear tests. The comparison shows that the failure loads obtained from the analyses are close in consistence with those obtained from the experiments.


Author(s):  
Noman Khandoker ◽  
Monir Takla ◽  
Thomas Ting

Simple spot weld connection models are desirable in huge and complicated finite element models of automotive body-in-white structures which generally contains thousands of spot weld joints. Hence, in this paper six different individual spot weld joint finite element models simplified in terms of their geometric and constitutive representations were developed including the one that is currently used in automotive industries. The stiffness characteristics of these developed models were compared with the experimental results obtained following a simple strategy to design the welded joint based on the desired mode of nugget pull out failure. It was found that the current spot weld modeling practice in automotive industry under predict the maximum joint strength nearly by 50% for different loading conditions. The computational costs incurred by the developed models in different loading conditions were also compared. Hence, a suitable model for spot welded joints is established which is very simple to develop but relatively cheap in terms of computational costs.


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