Research on Optimization of Excavating Seguence for Dawangou Tunnel

2013 ◽  
Vol 353-356 ◽  
pp. 3703-3706
Author(s):  
Chang Yu Jin ◽  
Pan Pan Zhao ◽  
Chun Fu Xiang ◽  
Zi Feng Xia ◽  
Long Bin Dong ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Numerical Analysis ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Brittle Failure ◽  
Hard Rock ◽  
Local Energy ◽  
Change Trend

In response to the limitation of conventional index for stability and optimal design of underground rock mass engineering. The new evaluating indicator, local energy release rate, which can analysis the energy release intensity in the process of the brittle failure of hard rock is used in numerical analysis. Numerical simulation of construction sequence was studied for Dawangou tunnel using energy release rate index and a new constitutive model reflecting the brittle failure of hard rock. Based on the change trend of energy release rate, rock displacement and plastic zone, an optimization excavation is suggested. The optimal excavating sequence could serve as reference in the design and construction.

On the Energy Release Rate of Elliptical Cracks in Anisotropic Elastic Media

2003 ◽  
Vol 19 (1) ◽  
pp. 233-239
Author(s):  
Yibin Xue ◽  
Jianmin Qu
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Crack Opening Displacement ◽  
Release Rate ◽  
Crack Opening ◽  
Average Energy ◽  
Local Energy ◽  
Opening Displacement ◽  
Work Done ◽  
Elliptical Cracks

ABSTRACTThis brief note discusses some issues related to the calculation of energy release rate for elliptical cracks in anisotropic solids. By using the Stroh formalism, analytical expressions of the energy release rate are obtained for elliptical cracks in an unbounded anisotropic solid. Because of material anisotropy and geometric asymmetry of the crack, the local energy release rate varies along the crack front. The average energy release rate can be obtained by integrating the local energy release rate over the entire crack front. On the other hand, the total work done by the crack-surface traction on the entire crack opening displacement can be easily evaluated once the crack opening displacement is known. It is shown that the average energy release rate is equal to the rate of change per unit crack area increment of the work done by the external load on the crack opening displacement.

scholarly journals The surface-forming energy release rate versus the local energy release rate

2017 ◽  
Vol 175 ◽  
pp. 86-100 ◽  
Author(s):  
Si Xiao ◽  
He-ling Wang ◽  
Bin Liu ◽  
Keh-Chih Hwang
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Local Energy ◽  
Rate Versus

scholarly journals A critical local energy release rate criterion for fatigue fracture of elastomers

2011 ◽  
Vol 49 (21) ◽  
pp. 1518-1524 ◽  
Author(s):  
Samy Mzabi ◽  
Daniel Berghezan ◽  
Stéphane Roux ◽  
Francois Hild ◽  
Costantino Creton
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Fatigue Fracture ◽  
Release Rate ◽  
Local Energy ◽  
Energy Release Rate Criterion ◽  
Rate Criterion

Based on ANSYS the Application of Virtual Crack Close Technique in the Calculation of Strain Energy Release Rate in Interface Crack

2012 ◽  
Vol 178-181 ◽  
pp. 2444-2450
Author(s):  
Chen Cheng ◽  
Shui Wan
Keyword(s):  
Numerical Analysis ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Analysis Method ◽  
Total Strain Energy ◽  
Numerical Analysis Method

Computation of the energy release rate, based on the FEA software ANSYS, with the virtual crack close technique, is studied. To reduce post-processing workload, the spring element is imposed at the cracktip. In practical applications, COMBIN14 spring elements are adopted to set up the finite element model. Then, the numerical analysis method is applied in interface crack. But the calculaed strain energy release rates are pseudo values, and only the total strain energy release rate convergences. At last, two numerical experiments are presented to validate this method. The results show that the calculated values of the total strain energy release rate are well with the theoretical values. This numerical analysis method is an efficient and accurate numerical analysis method.

Failure Prediction of Graphite/Epoxy Laminates With Induced Intermittent Surge in Applied Load During Fatigue

2001 ◽  
Author(s):  
Diwakar N. Kedlaya ◽  
Assimina A. Pelegri
Keyword(s):  
Numerical Simulation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Composite Laminates ◽  
Damage Accumulation ◽  
Applied Load ◽  
Damage Growth ◽  
Mode Mixity ◽  
Accumulation Of Damage

Abstract An analytical model, backed by numerical simulation, describing the behavior of the energy release rate of composite laminates subjected to fatigue overloads is presented. The model establishes that accumulation of damage due to intermittent surge in applied load reduces the energy release rate, G, of the material. Thus, in the case of cyclic loading with overloads, it is essential to model the failure using a damage growth law that incorporates the damage accumulation due to the overloads. The results obtained in this study, have no restrictive assumptions regarding the specimen or the delamination thickness, T and h respectively, and are presented over varying mode-mixity and h/T ratios.

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