The Asymptotic Elastic-Viscoplastic Field at Mode I Dynamic Propagating Crack-Tip

2007 ◽  
pp. 817-820
Author(s):  
Zhen Qing Wang ◽  
Ji Bin Wang ◽  
Wen Yan Liang ◽  
Juan Su
Keyword(s):  
Crack Tip ◽  
Mode I ◽  
Dynamic Propagating ◽  
Propagating Crack

The Asymptotic Elastic-Viscoplastic Field at Mode I Dynamic Propagating Crack-Tip

2007 ◽  
Vol 348-349 ◽  
pp. 817-820
Author(s):  
Zhen Qing Wang ◽  
Ji Bin Wang ◽  
Wen Yan Liang ◽  
Juan Su
Keyword(s):  
Crack Tip ◽  
Viscosity Coefficient ◽  
Plastic Strain Rate ◽  
Mode I ◽  
Mode I Crack ◽  
Moving Crack ◽  
Dynamic Propagating ◽  
Propagating Crack ◽  
Hardening Condition ◽  
Elastic Unloading

The viscosity of material is considered at propagating crack-tip. Under the assumption that the artificial viscosity coefficient is in inverse proportion to the power law of the plastic strain rate, an elastic-viscoplastic asymptotic analysis is carried out for moving crack-tip fields in power-hardening materials under plane-strain condition. A continuous solution is obtained containing no discontinuities. The variations of the numerical solution are discussed for mode I crack according to each parameter. It is shown that stress and strain both possess exponential singularity. The elasticity, plasticity and viscosity of material at the crack-tip only can be matched reasonably under linear-hardening condition. The tip field contains no elastic unloading zone for mode I crack.

Perfect elastic-viscoplastic field at mode I dynamic propagating crack-tip

2007 ◽  
Vol 28 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Zhen-qing Wang ◽  
Wen-yan Liang ◽  
Bo Zhou ◽  
Juan Su
Keyword(s):  
Crack Tip ◽  
Mode I ◽  
Dynamic Propagating ◽  
Propagating Crack

The Elastic-Viscoplastic Field Near Mode II Dynamic Propagating Crack-Tip of Interface in Double Dissimilar Materials

2010 ◽  
Vol 97-101 ◽  
pp. 625-628
Author(s):  
Wen Yan Liang ◽  
Zhen Qing Wang ◽  
Hong Qing Lv
Keyword(s):  
Interface Crack ◽  
Crack Tip ◽  
Dissimilar Materials ◽  
Viscosity Coefficient ◽  
Mode Ii ◽  
Crack Tip Field ◽  
Displacement Potential ◽  
Viscosity Effect ◽  
Dynamic Propagating ◽  
Propagating Crack

The existence of viscosity effect at the interface of double dissimilar materials has an important impact to the distribution of interface crack-tip field and the properties variety of the interface itself. The singular is considered in crack-tip, and the elastic-viscoplastic governing equations of double dissimilar materials at quasi-static propagating interface crack-tip field are established. The displacement potential function and boundary condition of interface crack-tip are introduced, and the numerical analysis of rigid-elastic viscoplastic interface for mode II are worked out. The stress-strain fields are obtained at the crack-tip and the variations of solutions are discussed according to each parameter. The numerical results show that the viscosity effect is a main factor of interface propagating crack-tip field, and the interface crack-tip is a viscoplastic field that is governed by viscosity coefficient、Mach number and singular factor.

Asymptotic Field near the Tip of a Mode I Quasi-Statically Propagating Crack in Rate-Sensitive Materials

2010 ◽  
Vol 452-453 ◽  
pp. 141-144
Author(s):  
Jia Lei Li ◽  
Bin Jia ◽  
Zhen Qing Wang ◽  
Bao Jun Pang
Keyword(s):  
Power Law ◽  
Crack Tip ◽  
Viscosity Coefficient ◽  
Mode I ◽  
Crack Tip Field ◽  
Plane Stress Condition ◽  
Propagating Crack ◽  
Power Law Function ◽  
Constitutive Mode ◽  
Hardening Coefficient

An elastic-viscoplastic constitutive mode was adopted to analyze asymptotically the tip field of a mode I quasi-statically propagating crack in rate-sensitive materials under plane stress condition. Under the assumption that the viscosity coefficient is a power law function of the rate of effective plastic strain, it was obtained through dimension match that the crack tip field possesses power law singularity. And the singularity exponent is uniquely determined by the power law exponent in the supposed viscosity coefficient. The elasticity, plasticity and viscosity of material at crack-tip only can be matched reasonably under linear-hardening condition. Variations of crack tip field characters according to each material parameter were discussed by means of numerical computation. The stress intensity is dominated by the material viscosity whereas the hardening coefficient has less significant influence on tip field. Furthermore, the solution can be transformed to the elastic-nonlinear-viscous one of Hui and Riedel if the limit case of zero hardening coefficient is considered.

The Perfect Elastic-Viscoplastic Field at Mode I Quasi-Static Propagating Crack-Tip in Rate-Sensitive Material

2006 ◽  
Vol 324-325 ◽  
pp. 17-20 ◽  
Author(s):  
Wen Yan Liang ◽  
Yong Jun Wang ◽  
Zhen Qing Wang ◽  
Hong Qing Lv
Keyword(s):  
Plastic Material ◽  
Crack Tip ◽  
Viscosity Coefficient ◽  
Characteristic Parameter ◽  
Constitutive Relationship ◽  
Plastic Strain Rate ◽  
Mode I ◽  
Sensitive Material ◽  
Strain Fields ◽  
Propagating Crack

Under the assumption that the artificial viscosity coefficient at the propagating crack tip is in inverse proportion to power law of the plastic strain rate, a rate-sensitive constitutive relationship is derived for perfect elastic-plastic material. With the adoption of the rate-sensitive constitutive relationship, it is asymptotically investigated the propagating tip fields of plane strain mode I. And the quasi-static equations are obtained separately governing the stress and strain fields at the crack-tip by means of Airy stress function. Numerical calculations of governing equations are carried out by double parameters shooting, with selections of appropriate values of each characteristic parameter by combinations of boundary, and the fully continuous stress-strain fields are obtained at the crack-tip. The analytical and computational results indicate that viscosity effect is an important factor in crack-tip fields.

Asymptotic analysis of mode I propagating crack-tip field in a creeping material

2003 ◽  
Vol 2 (1) ◽  
pp. 76-81
Author(s):  
Zhen-qing Wang ◽  
Qi-cheng Zhao ◽  
Wen-yan Liang ◽  
Zhang-jian Fu
Keyword(s):  
Asymptotic Analysis ◽  
Crack Tip ◽  
Mode I ◽  
Crack Tip Field ◽  
Propagating Crack
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