Asphalt Material Creep Behavior

A set of finite element simulations was performed to analyze the creep behavior of an elastic–perfectly plastic hemisphere in contact with a rigid flat. This study focuses on the time-dependent stress relaxation of a fully plastic asperity. Assuming a Garofalo (hyperbolic sine) type material creep law, the asperity shows two distinct phases of relaxation. In the first phase, the asperity creeps with an accelerated creep rate and shows a contact area increase similar to that of a cylindrical geometry. In the second phase, no contact area change can be measured and the asperity creeps with a slower rate. Empirical evolution laws for the asperity creep behavior are presented, analyzing the influence of both material and geometrical parameters. The results are interpreted in terms of transient friction.

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Stress Analysis in a Joint with Functionally Graded Materials Considering Material Creep Behavior

Materials Science Forum ◽

10.4028/www.scientific.net/msf.308-311.948 ◽

1999 ◽

Vol 308-311 ◽

pp. 948-956 ◽

Cited By ~ 1

Author(s):

Yu Ying Yang

Keyword(s):

Stress Analysis ◽

Functionally Graded Materials ◽

Creep Behavior ◽

Functionally Graded ◽

Graded Materials ◽

Material Creep

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Creep Modeling of Polyvinyl Chloride Bolted Flange Joints

Volume 9: Mechanics of Solids, Structures and Fluids; NDE, Structural Health Monitoring and Prognosis ◽

10.1115/imece2017-72406 ◽

2017 ◽

Author(s):

Zijian Zhao ◽

Rahul Palaniappan Kanthabhabha Jeya ◽

Abdel-Hakim Bouzid

Keyword(s):

Polyvinyl Chloride ◽

Creep Behavior ◽

Compressive Load ◽

Dissimilar Materials ◽

Operating Conditions ◽

Relaxation Behavior ◽

Creep Model ◽

Compression Creep ◽

Material Creep ◽

Bolted Flange

Alike other polymer material, PolyVinyl Chloride (PVC) shows a clear creep behavior, the rate of which is influenced by temperature, load and time. Polyvinyl chloride bolted flange joints undergo relaxation under compression for which the material creep properties are different than those under tension. Since the sealing capacity of a flanged gasketed joint is impacted by the amount of relaxation that takes place, it is important to properly address and predict the relaxation behavior due to flange creep under compression and reduce the chances of leakage failure of PVC flange joints. The main objective is study the creep behavior of PVC flanges under the influence of normal operating conditions. This is achieved by developing a PVC creep model based on creep test data under various compressive load, temperature and time. A simulation of a PVC flange relaxation behavior bot numerically and experimentally is conducted on an NPS 3 class 150 bolted flange joint of dissimilar materials one made of PVC material and the other one by steel SA105. The study also provides a clear picture on how the compression creep data on Ring specimen may be utilized for predicating the flange performance under various operating temperatures with time.

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Non-Rigid Rotating Motion Effect on Creep Behavior for Infinite Cylinders under Thermomechanical Loading

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.105.137 ◽

2021 ◽

Vol 105 ◽

pp. 137-143

Author(s):

Hamideh Seddighi ◽

Mohammad Parhizkar Yaghoobi ◽

Mehdi Ghannad

Keyword(s):

Creep Behavior ◽

Radial Displacement ◽

Rigid Motion ◽

Structural Behavior ◽

Uniform Heat Flux ◽

Kinematic Equation ◽

Rigidity Parameter ◽

Material Creep ◽

Rate Form ◽

History Of

The effect of non-rigid motion on creep analysis for cylinders have been investigated. inner surface of the cylinder is exposed to a uniform heat flux and for cooling the outer surface of the cylinder an air steam is applied to it. The cylinder is subjected to a body force. That produced by rotating cylinder about its own axis. It is assumed the cylinder is not rigid. Therefore, using equations of equilibrium, stress–strain and kinematic equation, governed equation which includes redial displacement and creep strains, is obtained. The material creep constitutive model is defined by the Bailey-Norton time-dependent creep law. From a solution consisting of analytical solution and iteration method has been used to obtain history of stresses and deformations during creep evolution of rotating cylinders. Therefore, Prandtle-Ruess equation substituted in equilibrium equation in the rate form, the radial displacement rate is obtained for plane strain condition. To investigate the effect of non-rigidity, the non-rigidity parameter (ζ) is defined and its effect on the creep behavior of the structure is investigated. It was revealed that Considering the structure as rigid does neglect the amount of stresses and radial displacement. History of stresses and displacement during 20 years are studied and it is observed that the changes have not accrued in recent years. The effect of velocity is another parameter that is investigated its effect on structural behavior during the time. it was revealed that, velocity has significant effect on structural behavior which cause trend of variation behavior change from linear to polynomial curve.

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