A viscoplastic constitutive model with strain rate variables for asphalt mixtures—numerical simulation

Soil-liquefaction-related hazards can damage structures or lead to an extensive loss of life and property. Therefore, the stability and safety of structures against soil liquefaction are essential for evaluation in earthquake design. In practice, the simplified liquefaction analysis procedure associated with numerical simulation analysis is the most used approach for evaluating the behavior of structures or the effectiveness of mitigation plans. First, the occurrence of soil liquefaction is evaluated using the simplified procedure. If soil liquefaction occurs, the resulting structural damage or the following mitigation plan is evaluated using the numerical simulation analysis. Rational and comparable evaluation results between the simplified liquefaction analysis procedure and the numerical simulation analysis are achieved by ensuring that the liquefaction constitutive model used in the numerical simulation has a consistent liquefaction resistance with the simplified liquefaction analysis procedure. In this study, two frequently used liquefaction constitutive models (Finn model and UBCSAND model) were calibrated by fitting the liquefaction triggering curves of most used simplified liquefaction analysis procedures (NCEER, HBF, JRA96, and T-Y procedures) in Taiwan via FLAC program. In addition, the responses of two calibrated models were compared and discussed to provide guidelines for selecting an appropriate liquefaction constitutive model in future projects.

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Procedure for the Selection of Rubber Compound in Rubber-Metal Springs for Vibration Isolation

Polymers ◽

10.3390/polym12081737 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1737

Author(s):

Milan Banić ◽

Dušan Stamenković ◽

Aleksandar Miltenović ◽

Dragan Jovanović ◽

Milan Tica

Keyword(s):

Numerical Simulation ◽

Constitutive Model ◽

Vibration Isolation ◽

Correct Selection ◽

Virtual Experiment ◽

Rubber Compound ◽

Key Factor ◽

Railway Engineering ◽

Selection Of

The selection of a rubber compound has a determining influence on the final characteristics of rubber-metal springs. Therefore, the correct selection of a rubber compound is a key factor for development of rubber-metal vibration isolation springs with required characteristics. The procedure for the selection of the rubber compound for vibration isolation of rubber-metal springs has been proposed, so that the rubber-metal elements have the necessary characteristics, especially in terms of deflection. The procedure is based on numerical simulation of spring deflection with Bergström-Boyce constitutive model in virtual experiment, with a goal to determine which parameters of the constitutive model will lead to spring required deflection. The procedure was verified by case study defined to select rubber compound for a rubber–metal spring used in railway engineering.

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Constitutive Modeling for Elevated Temperature Flow Behavior of ZHMn34-2-2-1 Manganese Brass

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.872.30 ◽

2017 ◽

Vol 872 ◽

pp. 30-37

Author(s):

Meng Han Wang ◽

Kang Wei ◽

Xiao Juan Li

Keyword(s):

Constitutive Model ◽

Strain Rate ◽

Flow Behavior ◽

Peak Stress ◽

Strain Rates ◽

Hollomon Parameter ◽

Prediction Ability ◽

Absolute Relative Error ◽

Deformation Behaviors ◽

State Stress

The hot compressive deformation behaviors of ZHMn34-2-2-1 manganese brass are investigated on Thermecmastor-Z thermal simulator over wide processing domain of temperatures (923K-1073K) and strain rates (0.01s-1-10s-1). The true stress-strain curves exhibit a single peak stress, after which the stress monotonously decreases until a steady state stress occurs, indicating a typical dynamic recrystallization. A revised constitutive model coupling flow stress with strain, strain rate and deformation temperature is established with the material constants expressed by polynomial fitting of strain. Moreover, better prediction ability of the constitutive model is achieved by implementation of a simple approach for modified the Zener-Hollomon parameter considering the compensation of strain rate and temperature increment. By comparing the predicted and experimented values, the correlation coefficient and mean absolute relative error are 0.997 and 2.363%, respectively. The quantitative statistical results indicate that the proposed constitutive model can precisely characterize the hot deformation behavior of ZHMn34-2-2-1 manganese brass.

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DP600 dual phase steel thermo-elasto-plastic constitutive model considering strain rate and temperature influence on FEM residual stress analysis of laser welding

Journal of Manufacturing Processes ◽

10.1016/j.jmapro.2018.07.006 ◽

2018 ◽

Vol 35 ◽

pp. 407-419 ◽

Cited By ~ 3

Author(s):

S. Liu ◽

A. Kouadri-Henni ◽

A. Gavrus

Keyword(s):

Residual Stress ◽

Constitutive Model ◽

Laser Welding ◽

Strain Rate ◽

Stress Analysis ◽

Dual Phase Steel ◽

Dual Phase ◽

Temperature Influence ◽

Residual Stress Analysis

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Monstars on Glaciers

Journal of Glaciology ◽

10.3189/s0022143000005153 ◽

1983 ◽

Vol 29 (101) ◽

pp. 70-77 ◽

Cited By ~ 1

Author(s):

J. F. Nye

Keyword(s):

Numerical Simulation ◽

Strain Rate ◽

Tensor Field ◽

Pure Shear ◽

Glacier Surface ◽

Isotropic Point ◽

Different Types ◽

Isolated Points ◽

Principal Directions ◽

Structurally Stable

AbstractIsotropic points are structurally stable features of any complicated field of stress or strain-rate, and therefore will almost always be present on the surface of a glacier. A given isotropic point for strain-rate will belong to one of six different classes, depending on the pattern (lemon, star, or monstar) of principal directions and the contours (ellipses or hyperbolas) of constant principal strain-rate values in its neighbourhood. The central isotropic point on a glacier should theoretically have a monstar pattern, but the contours around it may sometimes be elliptic and sometimes hyperbolic. Nearby, but not coincident with it there will be an isotropic point for stress. This will also have a monstar pattern but, in contrast to the strain-rate point, the contours around it must be hyperbolic. Published examples are consistent with these conclusions. In addition to isotropic points for strain-rate a glacier surface will contain isolated points of pure shear; these also can be classified into six different types. Stable features of this kind give information about the essential structure of a tensor field and form useful points of comparison between observation and numerical simulation.

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