The Effects of Strain and Stress State in Hot Forming of Mg AZ31 Sheet

2012 ◽  
pp. 301-306 ◽  
Author(s):  
Paul A. Sherek ◽  
Alexander J. Carpenter ◽  
Louis G. Hector ◽  
Paul E. Krajewski ◽  
Jon T. Carter ◽  
...  
Keyword(s):  
Stress State ◽  
Hot Forming ◽  
Az31 Sheet

The effects of strain and stress state in hot forming of mg AZ31 sheet

2012 ◽  
pp. 301-306 ◽  
Author(s):  
Paul A. Sherek ◽  
Alexander J. Carpenter ◽  
Louis G. Hector ◽  
Paul E. Krajewski ◽  
Jon T. Carter ◽  
...  
Keyword(s):  
Stress State ◽  
Hot Forming ◽  
Az31 Sheet

Influence of Temperature and Loading Rate on the Forming Limit Behaviour of Twin-Roll Cast, Rolled and Heat-Treated AZ31 as a Function of the Stress State

2016 ◽  
Vol 684 ◽  
pp. 67-73 ◽  
Author(s):  
Franz Berge ◽  
Thorsten Henseler ◽  
Christina Krbetschek ◽  
Madlen Ullmann ◽  
Rudolf Kawalla
Keyword(s):  
Stress State ◽  
Loading Rate ◽  
Sheet Thickness ◽  
Forming Limit ◽  
Limit Values ◽  
Loading Rates ◽  
Economic Production ◽  
Az31 Sheet ◽  
Limit Behaviour ◽  
Stress States

Magnesium and its alloys have high potential for lightweight applications in the automotive and aerospace industries. In order to design parts for new applications with optimized mechanical properties and higher, more economic production rates, the forming limit behaviour of thin sheets (t < 1.0 mm) has to be known for different temperatures and loading rates. In this study, forming limit curves of 0.8 mm thick AZ31 sheet were measured for deformation at 200 °C and 250 °C and at loading rates of 1 mm/s and 10 mm/s with the Nakajima test. The investigations showed that an increase in temperature from 200 °C to 250 °C tends toward higher forming limit values for all stress states. In contrast, an increase in the loading rate from 1 mm/s to 10 mm/s induces a reduction in formability. It can be seen that the temperature, loading rate, and stress state influence the force-distance curves, the distribution of the local major strains, and the sheet thickness reduction.

Short Stress State Questionnaire

2015 ◽  
Vol 31 (1) ◽  
pp. 20-30 ◽  
Author(s):  
William S. Helton ◽  
Katharina Näswall
Keyword(s):  
Stress State ◽  
Factor Structure ◽  
Human Performance ◽  
Self Report ◽  
Confirmatory Factor ◽  
Stress States ◽  
Related Stress ◽  
Using Data ◽  
Task Conditions ◽  
Multiple Samples

Conscious appraisals of stress, or stress states, are an important aspect of human performance. This article presents evidence supporting the validity and measurement characteristics of a short multidimensional self-report measure of stress state, the Short Stress State Questionnaire (SSSQ; Helton, 2004 ). The SSSQ measures task engagement, distress, and worry. A confirmatory factor analysis of the SSSQ using data pooled from multiple samples suggests the SSSQ does have a three factor structure and post-task changes are not due to changes in factor structure, but to mean level changes (state changes). In addition, the SSSQ demonstrates sensitivity to task stressors in line with hypotheses. Different task conditions elicited unique patterns of stress state on the three factors of the SSSQ in line with prior predictions. The 24-item SSSQ is a valid measure of stress state which may be useful to researchers interested in conscious appraisals of task-related stress.

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