Dynamic Stress-Strain Behavior of AZ91 Alloy at High-Strain Rate

The present paper is concerned with constitutive modeling of the compressive stress-strain behavior of selected polymers at strain rates from 10-3 to 103/s using a modified Ramberg-Osgood equation. High strain-rate compressive stress-strain curves up to strains of nearly 0.08 for four different commercially available extruded polymers were determined on the standard split Hopkinson pressure bar (SHPB). The low and intermediate strain-rate compressive stress-strain relations were measured in an Instron testing machine. Six parameters in the modified Ramberg-Osgood equation were determined by fitting to the experimental stress-strain data using a least-squares fit. It was shown that the monotonic compressive stress-strain behavior over a wide range of strain rates can successfully be described by the modified Ramberg-Osgood constitutive model. The limitations of the model were discussed.

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Stress-Strain Behavior of Nylon-Carbon Composite Subjected to High Strain Rate Impact Loading

Journal of Energy and Power Engineering ◽

10.17265/1934-8975/2015.09.005 ◽

2015 ◽

Vol 9 (9) ◽

Author(s):

Noori Hassoon Mohammed Al-Saadi

Keyword(s):

High Strain Rate ◽

Strain Rate ◽

Impact Loading ◽

High Strain ◽

Carbon Composite ◽

Stress Strain ◽

Strain Behavior

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Dynamic Stress-Strain Behavior of AZ91 Alloy at High-Strain Rate

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.89 ◽

2007 ◽

Vol 546-549 ◽

pp. 89-92 ◽

Cited By ~ 4

Author(s):

Gui Ying Sha ◽

En Hou Han ◽

Yong Bo Xu ◽

Lu Liu

Keyword(s):

Flow Stress ◽

Strain Rate ◽

Dynamic Stress ◽

Split Hopkinson Pressure Bar ◽

Az91 Alloy ◽

Hopkinson Pressure Bar ◽

Stress Strain ◽

Strain Rate Effects ◽

Strain Behavior ◽

Pressure Bar

The dynamic stress-strain behavior of the AZ91 alloys in different treatment conditions (as-cast, T4 and T6) was investigated by means of split Hopkinson pressure bar. It was found that the flow stress increased at first, and then declined with the strain rate increasing at the range of 102~103s-1 for the alloys in these three conditions. And the alloys exhibited both positive and negative strain rate effects. The former was caused by strain rate strengthening and the latter was caused by strain rate weakening. However the flow stress for the alloy in aged condition at the same strain rate was higher than both of the alloys in as-cast and solution conditions. The study also showed that the maximum strains of the alloys in different conditions increased with the strain rate increasing, and the strain rate to fracture for the alloy in solution condition was higher than those of other two alloys. The work-hardening of α–Mg matrix and the reinforcement of β-Mg17Al12 phases led to the strengthening of the alloy, while thermal softening of matrix, the fracture of β phases and initiation and propagation of the cracks were responsible for the weakening of the alloy.

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