Modeling of failure mode of laser welds in lap-shear specimens of HSLA steel sheets

2011 ◽  
Vol 78 (2) ◽  
pp. 374-396 ◽  
Author(s):  
Jaewon Lee ◽  
Kamran Asim ◽  
Jwo Pan
Keyword(s):  
Failure Mode ◽  
Hsla Steel ◽  
Steel Sheets ◽  
Lap Shear ◽  
Laser Welds

Failure Mode and Fatigue Behavior of Dissimilar Laser Welds in Lap-Shear Specimens of Low Carbon Steel and HSLA Steel Sheets

2015 ◽  
Vol 8 (3) ◽  
pp. 912-917
Author(s):  
Zheng-Ming Su ◽  
Pai-Chen Lin ◽  
Wei-Jen Lai ◽  
Jwo Pan
Keyword(s):  
Carbon Steel ◽  
Failure Mode ◽  
Fatigue Behavior ◽  
Hsla Steel ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Steel Sheets ◽  
Lap Shear ◽  
Laser Welds

Failure Mode of Laser Welds in Lap-Shear Specimens of HSLA Steel

2010 ◽  
Author(s):  
Kamran Asim ◽  
Jaewon Lee ◽  
Jwo Pan
Keyword(s):  
Failure Mode ◽  
Hsla Steel ◽  
Lap Shear ◽  
Laser Welds

Failure Mode and Fatigue Behavior of Ultrasonic Spot Welds with Adhesive in Lap-Shear Specimens of Magnesium and Steel Sheets

2013 ◽  
Vol 6 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Wei-Jen Lai ◽  
Jwo Pan ◽  
Zhili Feng ◽  
Michael Santella ◽  
Tsung-Yu Pan
Keyword(s):  
Failure Mode ◽  
Fatigue Behavior ◽  
Spot Welds ◽  
Steel Sheets ◽  
Lap Shear

Fatigue behavior of laser welds in lap-shear specimens of high strength low alloy steel sheets

2014 ◽  
Vol 61 ◽  
pp. 283-296 ◽  
Author(s):  
Kamran Asim ◽  
Kulthida Sripichai ◽  
Jwo Pan
Keyword(s):  
Alloy Steel ◽  
Fatigue Behavior ◽  
High Strength ◽  
Low Alloy Steel ◽  
Steel Sheets ◽  
Lap Shear ◽  
Laser Welds

scholarly journals Failure mode and fatigue behavior of weld-bonded lap-shear specimens of magnesium and steel sheets

2015 ◽  
Vol 75 ◽  
pp. 184-197 ◽  
Author(s):  
Wei-Jen Lai ◽  
Jwo Pan
Keyword(s):  
Failure Mode ◽  
Fatigue Behavior ◽  
Steel Sheets ◽  
Lap Shear

Failure Mode and Fatigue Behavior of Dissimilar Laser Welds in Lap-Shear Specimens of Aluminum and Copper Sheets

2014 ◽  
Vol 7 (3) ◽  
pp. 706-710 ◽  
Author(s):  
Wei-Jen Lai ◽  
Shin-Jang Sung ◽  
Jwo Pan ◽  
Yunan Guo ◽  
Xuming Su
Keyword(s):  
Failure Mode ◽  
Fatigue Behavior ◽  
Lap Shear ◽  
Laser Welds

scholarly journals Ultrasonic Spot Welding of Similar and Dissimilar Alloys for Automotive Applications

2021 ◽  
Author(s):  
Andrew Macwan
Keyword(s):  
Diffusion Layer ◽  
Spot Welding ◽  
Frictional Heating ◽  
Hsla Steel ◽  
Weight Ratio ◽  
High Strength ◽  
Phase Identification ◽  
Welding Time ◽  
Interface Diffusion ◽  
Lap Shear

Lightweighting has been regarded as a key strategy in the automotive industry to improve fuel efficiency and reduce anthropogenic environment-damaging, climate-changing, and costly emissions. Magnesium (Mg) alloys and Aluminum (Al) alloys are progressively more used in the transportation industries to reduce the weight of vehicles due to their high strength-to-weight ratio. Similarly, high strength low alloy (HSLA) steel is widely used to reduce gauge thickness and still maintain the same strength, and thereby reduce vehicle weight as well. A multi-material design of automotive structures and parts inevitably involve similar Mg-to-Mg and dissimilar Mg-to-Al, Al-to-steel, and Mg-to-Cu joints. Ultrasonic spot welding (USW) – a solid-state joining technique has recently received significant attention due to its higher efficiency in comparison with conventional fusion welding techniques. In this study, USW was used to generate similar joints of low rare-earth containing ZEK100 Mg alloy sheets and dissimilar ZEK100-to-Al5754, Al6111-to-HSLA steel, and Mg-to-Cu joints at different levels of welding energy or welding time. To optimize welding process and identify key factors affecting the weld strength, microstructural evolution, microhardness test, tensile lap shear test, fatigue test, and fracture analysis were performed on similar and dissimilar ultrasonic spot welded (USWed) joints. Dynamic recrystallization and grain coarsening were observed during Mg-to-Mg similar welding while rapid formation and growth of interface diffusion layer were observed in all dissimilar joints in the present study. It was due to significantly high strain rate (~103 s-1) and high temperature generated via frictional heating during USW. The interface diffusion layer was analyzed by SEM, EDS and XRD phase identification techniques which showed the presence of eutectic structure containing intermetallic compounds (IMCs). As a result, brittleness at the interface increased. The Zn coating in dissimilar USWed Al-to-steel joints eliminated the formation of brittle IMCs of Al-F, which were replaced by relatively ductile AlZn eutectic. The optimum welding energy or welding time during similar and dissimilar USW of lightweight alloys with a sheet thickness of 1-2 mm was in the range of ~500 J to 2000 J (~0.25 s to 1 s).

scholarly journals Microstructure and mechanical properties of an ultrasonic spot welded aluminum alloy: the effect of welding energy

2021 ◽  
Author(s):  
He Peng ◽  
Daolun Chen ◽  
Xianquan Jiang
Keyword(s):  
Shear Strength ◽  
Aluminum Alloy ◽  
Cyclic Loading ◽  
Crack Growth ◽  
Failure Mode ◽  
Spot Welding ◽  
Energy Levels ◽  
Lap Shear Strength ◽  
Pull Out ◽  
Lap Shear

The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique–ultrasonic spot welding (USW)–at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain sizes at lower levels of welding energy. The tensile lap shear strength, failure energy, and critical stress intensity of the welded joints first increase, reach their maximum values, and then decrease with increasing welding energy. The tensile lap shear failure mode changes from interfacial fracture at lower energy levels, to nugget pull-out at intermediate optimal energy levels, and to transverse through-thickness (TTT) crack growth at higher energy levels. The fatigue life is longer for the joints welded at an energy of 1400 J than 2000 J at higher cyclic loading levels. The fatigue failure mode changes from nugget pull-out to TTT crack growth with decreasing cyclic loading for the joints welded at 1400 J, while TTT crack growth mode remains at all cyclic loading levels for the joints welded at 2000 J. Fatigue crack basically initiates from the nugget edge, and propagates with “river-flow” patterns and characteristic fatigue striations. Keywords: aluminum alloy; ultrasonic spot welding; EBSD; microstructure; tensile strength; fatigue

Bond Behaviour of FRCM Composites: Effects of High Temperature

2019 ◽  
Vol 817 ◽  
pp. 161-166
Author(s):  
Antonio Iorfida ◽  
Sebastiano Candamano ◽  
Fortunato Crea ◽  
Luciano Ombres ◽  
Salvatore Verre ◽  
...  
Keyword(s):  
High Temperature ◽  
Failure Mode ◽  
Failure Modes ◽  
Construction Materials ◽  
Mechanical Damage ◽  
High Density ◽  
Bond Behaviour ◽  
Bond Slip ◽  
Masonry Construction ◽  
Lap Shear

The fire remains one of the serious potential risks to most buildings and structures, as recently it’s been witnessed in Paris’ historic Notre Dame Cathedral and London’s Grenfell Tower. Concrete and masonry construction materials suffer physiochemical changes and mechanical damage caused by heating that is usually confined to the outer surface but can eventually compromise their load-bearing capacity. FRCM systems could provide when applied, supplemental fire insulation on pre-existing structural members, but there is a lack of knowledge about their properties in those conditions. This experimental work, thus, aims to evaluate the mechanical behaviour of carbon-FRCM and basalt-FRCM composites bonded to masonry substrate after high temperature exposure. Temperatures of 100 °C, 300 °C and 500 °C over a period of three hours were used to investigate the degradation of their mechanical properties. Single lap shear bond tests were carried out to evaluate the bond-slip response and failure modes. For all the tested temperatures higher peak stresses were measured for carbon-FRCM composite than basalt ones. Furthermore, low-density basalt-FRCM composite showed higher peak stresses and lower global slips up to 300 °C than high-density one. Carbon-FRCM composite failure mode was not effected by temperature. High-density basalt-FRCM composite showed a change in failure mode between 300 °C and 500 °C.

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