Short Term Stress — Strain Properties

2006 ◽  
pp. 109-172
Keyword(s):  
Short Term ◽  
Stress Strain

scholarly journals Mechanical Behavior of Red Sandstone under Incremental Uniaxial Cyclical Compressive and Tensile Loading

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Baoyun Zhao ◽  
Dongyan Liu ◽  
Tianzhu Huang ◽  
Wei Huang ◽  
Wei Liu
Keyword(s):  
Energy Dissipation ◽  
Mechanical Behavior ◽  
Strain Curve ◽  
Tensile Loading ◽  
Creep Model ◽  
Short Term ◽  
Stress Strain ◽  
Cycle Number ◽  
Red Sandstone ◽  
Residual Strains

Uniaxial experiments were carried out on red sandstone specimens to investigate their short-term and creep mechanical behavior under incremental cyclic compressive and tensile loading. First, based on the results of short-term uniaxial incremental cyclic compressive and tensile loading experiments, deformation characteristics and energy dissipation were analyzed. The results show that the stress-strain curve of red sandstone has an obvious memory effect in the compressive and tensile loading stages. The strains at peak stresses and residual strains increase with the cycle number. Energy dissipation, defined as the area of the hysteresis loop in the stress-strain curves, increases nearly in a power function with the cycle number. Creep test of the red sandstone was also conducted. Results show that the creep curve under each compressive or tensile stress level can be divided into decay and steady stages, which cannot be described by the conventional Burgers model. Therefore, an improved Burgers creep model of rock material is constructed through viscoplastic mechanics, which agrees very well with the experimental results and can describe the creep behavior of red sandstone better than the Burgers creep model.

Short-Term Test of ±55 ̊ Filament Wound GRE Composite Pipes under Multiaxial Stress Ratios

2014 ◽  
Vol 554 ◽  
pp. 371-375
Author(s):  
Krishnan Pranesh ◽  
M.S. Abdul Majid ◽  
Mohd Afendi ◽  
Haslan Marzuki ◽  
Mohd Nor Fakhzan Mohd Kazim
Keyword(s):  
Pressure Sensors ◽  
Axial Loading ◽  
Wall Stress ◽  
Strain Response ◽  
Short Term ◽  
Stress Strain ◽  
Filament Wound ◽  
Short Term Test ◽  
Stress Ratios ◽  
Composite Pipes

This paper discusses the the development of an automated pressure testing rig to perform a short term test; Ultimate Elastic Wall Stress (UEWS) for ±55 ̊ glass fibre reinforced epoxy (GRE) composite pipe under various stress ratios. The prototype is capable of determining the stress-strain response caused by the static and cyclic pressure. This developed rig is to provide an alternative solution for the current qualification procedure explained in ISO14692 through ASTM 2992. As part of the work, an automated testing rig powered by labview program is developed with the aid of pressure sensors, solenoid valves and strain gauges which are interfaced through hardware modules from National Instruments. The UEWS test for the five stress ratios namely pure hydrostatic (2H:1A), pure hoop (1H:0A), pure axial (0H:1A), hoop to axial (1H:1A) and quad hoop to axial loading (4H:1A) were performed upon the ±55° filament wound glass-reinforced epoxy pipes. The changes in the stress strain response are captured from the strain gauge measurements and the UEWS failure points are calculated for all the loading conditions. The failure envelope developed from the failure points can be used to predict the long term performance of the GRE pipes and provide the benchmark for the design of composite pipes under various stress ratios.

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