A three-dimensional (3D) finite element (FE) model is applied to predict the temperature evolution in the laser welding of galvanized high-strength steels in a zero-gap lap joint configuration. A rotary Gaussian volumetric heat source model is introduced to simulate the laser energy input. The temperature data measured by thermocouples are used to verify the boundary conditions of the thermal m...

1 Associate Research Fellow,Center for Research on Earthquake Engineering (NCREE), Chinese Taiwan 2 Professor, Dept. of Civil Engineering, Taiwan University, Taipei, Chinese Taiwan 3 Assistant Professor, Dept. of Civil and Environmental Engineering, University of Kaohsiung, Kaohsiung, Chinese Taiwan Email: [email protected] ABSTRACT : Ductility is the main attribute of steel moment connections...

Failure investigation was conducted on a bleed air connector of an aircraft engine that developed opening during service. The fabricated tubular structure wherein the flanges were circumferentially welded to bent pipe both ends. and made austenitic stainless steel AISI 321. Fractography study confirmed had failed by fatigue mechanism. Fatigue crack initiated at one weld joints. exact location i...

Friction stir welding (FSW) is a relatively new, solid-state, metal joining process invented by Wayne Thomas et al. at the Welding Institute of England (now TWI) in 1991 [1.] A FSW butt weld is made by following the joint-line of two butted pieces of material with a rotating tool while applying a significant down-force through the tool. Heating is provided at or near the tool-work interface by ...

Thermocouples are constructed of two dissimilar metals such as Chromel and Constantan (Type E) or Nicrosil and Nisil (Type N). The two dissimilar metals are bonded together on one end of both wires with a weld bead. This bead is exposed to the thermal environment of interest. If there is a temperature difference between the bead and the other end of the thermocouple wires, a voltage will appear...

Delayed coke drums are operated under severe conditions of cyclic heating and forced cooling that apply repetitive thermal stresses to the drum walls. It has long been recognized that the ultimate failure mechanism for coke drums is weld cracking due to low cycle fatigue caused by these thermal stresses. It is also known that coke drums distort and bulge in service and that these bulges can be ...

• Full-scale fatigue tests for a complex welded connection with failure at the weld root. Tests included different structural details and types. Crack propagation was visually observed. The results were analysed three stress-based local approaches. Among them, nominal stress approach resulted in smallest scatter. This paper investigates root strength of structures including severe force concent...

Joining of fixed appliance components has several applications in orthodontics. Joining attachments to archwires allows the clinician to transfer the point of force application to a location that is more advantageous from a biomechanical standpoint. Although several methods of joining attachments have been proposed, resistance spot welding and soldering have been the most commonly used procedur...