Analysis of thermal stresses and its effect in the multipass welding process of SS316L

In this work, simulation has been carried out for multipass Gas tungsten Arc Welding of SS316L and their effects were studied for thermal, and residual stresses and compared with experimental results. The sequentially coupled thermo-mechanical, transient thermal and static structural analysis was modelled using ANSYS with relevant Ansys Parametric Design Language coding. Infrared thermography camera was used to obtain the real time temperatures during the welding. The effect of temperatures and the induced residual stresses of the weldment is measured with X-Ray diffraction technique. Tensile residual stresses have been identified at fusion zone and compressive stresses at heat affected zone. Pass wise temperature measurements were taken from analysis and experiment the agreement with 7.24%. The agreement of measured and analysed residual stress had an agreement with 16.66%.

Tensile Fracture Behavior of Friction Stir Processed Al-7Si-0.3Mg Cast Alloy

Elimination of porosity and refinement of the normally coarse cast microstructure ofaluminium cast alloys by the intensive plastic deformation during friction stir processing (FSP) iswell known. However less is known about the mechanical behavior of the FS processed regionwhich contains zone/pass boundaries and macro/microstructure segregations. In the present study ofFS processed cast Al-7Si-0.3Mg alloy, microstructures featuring the deformed α-Al, fragmented Siparticles and their distribution in the processed region were related to the fracture paths duringtensile testing. It has been found that under the condition of a high rotation speed and minimum pinoverlap there is a strong upward flow of deformed cast material in thermomechanial affected zone.The arrays of Si particles in that flow have provided favorable paths for crack propagation duringtensile testing. As a result, tensile elongation and thus UTS values are low. The mechanism of thatupward flow and FSP conditions for reducing the flow and thus for improving properties of theprocessed region are discussed.

Criterion-Referenced Reliability and Equivalency Between the PACER and 1-Mile Run/Walk for High School Students

Background:To examine the Healthy Fitness Zone (pass/fail) criterion-referenced reliability (CRR) and equivalency (CRE) of the 1-mile run/walk (MRW) and Progressive Aerobic Cardiovascular Endurance Run (PACER) in adolescents (13 to 18 years).Methods:Seventy-six girls and 165 boys were randomly assigned to complete 2 trials of each test.Results:CRR for the boys on the MRW (Pa = 77%, κq = 0.53) was lower than on the PACER (Pa = 81%, κq = 0.63); girls were classified more similarly on the MRW (Pa = 83%, κq = 0.67) than on the PACER (Pa = 79%, κq = 0.58). The CRE between the MRW and PACER indicated boys (Pa = 77%, κq = 0.55) were classified more consistently on both tests than girls (Pa = 73%, κq = 0.46).Conclusions:No test provided greater consistency. Practitioners may consider other features, such as ease of administration, environmental conditions, and comparative use in the literature.