Re-distribution of residual stress in polymer extrusion: An eccentric approach

1994 ◽

Vol 52 ◽

pp. 628-629

Author(s):

J. Fang ◽

H. M. Chan ◽

M. P. Harmer

Keyword(s):

Residual Stress ◽

Single Phase ◽

Stress Relief ◽

Stress Recovery ◽

Surface Residual Stress ◽

Microscopic Mechanism ◽

Sic Particles ◽

Annealing Procedure ◽

The Difference ◽

Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

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Residual stress measurements and modeling of built-up Box-T sections

Thin-Walled Structures ◽

10.1016/j.tws.2020.107336 ◽

2021 ◽

Vol 160 ◽

pp. 107336

Author(s):

Ziqian Zhang ◽

Gang Shi ◽

Xuesen Chen ◽

Lijun Wang ◽

Le Zhou

Keyword(s):

Residual Stress ◽

Stress Measurements

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Comparative study of the effective parameters on residual stress relaxation in welded aluminum plates under cyclic loading

Mechanics & Industry ◽

10.1051/meca/2020061 ◽

2020 ◽

Vol 21 (5) ◽

pp. 505

Author(s):

Yousef Ghaderi Dehkordi ◽

Ali Pourkamali Anaraki ◽

Amir Reza Shahani

Keyword(s):

Residual Stress ◽

Cyclic Loading ◽

Stress Relaxation ◽

Stress Amplitude ◽

Cyclic Plasticity ◽

Mean Stress ◽

Effective Parameters ◽

Perfect Plasticity ◽

Residual Stress Relaxation ◽

Aluminum Plates

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.

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