OS1-4-3 Relation between principal stress direction and crack propagation direction in a quenched glass plate

2007 ◽  
Vol 2007.6 (0) ◽  
pp. _OS1-4-3-1-_OS1-4-3-6
Author(s):  
Kenichi Sakaue ◽  
Satoru Yoneyama ◽  
Masahisa Takashi
Keyword(s):  
Crack Propagation ◽  
Principal Stress ◽  
Glass Plate ◽  
Propagation Direction ◽  
Principal Stress Direction ◽  
Crack Propagation Direction ◽  
Stress Direction ◽  
Quenched Glass

Study on Hydraulic Fracturing Affected by Horizontal Principal Stress

2013 ◽  
Vol 423-426 ◽  
pp. 1467-1470
Author(s):  
Bo Huang ◽  
Tian Hui Ma ◽  
Ai Shan Li ◽  
Jian Qiu Sun ◽  
Liao Yuan Zhang
Keyword(s):  
Elastic Modulus ◽  
Hydraulic Fracturing ◽  
Crack Propagation ◽  
Weibull Distribution ◽  
Principal Stress ◽  
Poisson Ratio ◽  
Propagation Direction ◽  
Wing Crack ◽  
Crack Propagation Direction ◽  
Minimum Principal Stress

Adopted with the actual value of statistic geo-stress, using RFPA software to simulate the hydraulic fracturing of underground. The sample is treated as elastomers and simplified into plane problem, submit strength, elastic modulus, poisson ratio to weibull distribution. It could be found in figures that the size, length, extending direction of two crack is not identical. The cracks` forms grow into symmetry horizontal double-wing crack from the final result, besides, crack propagation direction is perpendicular to the direction of the minimum principal stress.

Automatic 3-D Crack Propagation Calculations in Industrial Components: A Pure Hexahedral versus a Combined Hexahedral-Tetrahedral Approach

2007 ◽  
Vol 348-349 ◽  
pp. 45-48
Author(s):  
Guido Dhondt
Keyword(s):  
Crack Propagation ◽  
Computing Time ◽  
Propagation Direction ◽  
Hexahedral Elements ◽  
Crack Propagation Direction ◽  
Low Weight ◽  
Out Of Plane ◽  
Hexahedral Meshes ◽  
Crack Faces

In recent years, increased loading and low weight requirements have led to the need for automatic crack tracing software. At MTU a purely hexahedral code has been developed in the nineties for Mode-I applications. It has been used extensively for all kinds of components and has proven to be very flexible and reliable. Nevertheless, in transition regions between complex components curved cracks have been observed, necessitating the development of mixed-mode software. Due to the curvature of the crack faces, purely hexahedral meshes are not feasible, and therefore a mixture of hexahedral elements at the crack tip, combined with tetrahedral in the remaining structure has been selected. The intention of the present paper is to compare both methods and to point out the strength and weaknesses of each regarding accuracy, complexity, flexibility and computing time. Furthermore, difficulties arising from the out-of-plane growth of the crack such as the determination of the crack propagation direction are discussed.

Fatigue Design Criteria as Function of the Principal Stress Direction Relative to the Weld Toe

2008 ◽  
Author(s):  
Inge Lotsberg
Keyword(s):  
Principal Stress ◽  
Hot Spot ◽  
Stress Conditions ◽  
Design Criteria ◽  
International Institute ◽  
Proportional Loading ◽  
Principal Stress Direction ◽  
Fatigue Design ◽  
Stress Direction ◽  
Weld Toe

For fatigue design it is necessary to provide guidelines on how to calculate fatigue damage at weld toes based on S-N data when the principal stress direction is different from that of the normal direction to the weld toe. Such stress conditions are found at details in different types of plated structures. Some different fatigue criteria for these stress conditions are presented in design standards on fatigue design. Criteria used by the International Institute of Welding (IIW), Eurocode, British Standard and in the DNV standards have been assessed against some relevant fatigue test data presented in the literature. Only proportional loading conditions have been considered here. (By proportional loading is understood that the principal stress direction is kept constant during a load cycle). An alternative equation for calculation of an equivalent or effective stress range based on stress normal to the weld toe and shear stress at the weld toe has been proposed. The proposed methodology can be used for nominal S-N curves and it can be used together with a hot spot stress S-N curve with stresses read out from finite element analysis. The different design criteria are presented in this paper together with recommendations on analysis procedure.

Powder strength after changes in principal stress direction

1994 ◽  
Vol 81 (1) ◽  
pp. 31-40 ◽  
Author(s):  
T. Dunstan ◽  
M. Jamebozorgi ◽  
S. Akbarian-Miandouab
Keyword(s):  
Principal Stress ◽  
Principal Stress Direction ◽  
Stress Direction

Comparison of Strain Rate Calculation Methods for Environmental Fatigue Correction Evaluation

2012 ◽  
Author(s):  
Seiji Asada
Keyword(s):  
Strain Rate ◽  
Principal Stress ◽  
Evaluation Method ◽  
Calculation Methods ◽  
Sample Problem ◽  
Nuclear Facility ◽  
Principal Stress Direction ◽  
Stress Direction ◽  
Rate Calculation ◽  
Fatigue Evaluation

A Code Case for procedure to determine strain rate and Fen for environmental fatigue evaluation is under preparation in the ASME BPV Committee on Construction of Nuclear Facility Components (III). The draft Code Case is to incorporate two methods for strain rate calculation. One is based on NB-3216.1 “Constant Principal Stress Direction” that comes from the JSME Environmental Fatigue Evaluation Method. The other is based on NB-3216.2 “Varying Principal Stress Direction” that was proposed by M. Gray et al. In this paper, both methods are explained and compared by using a sample problem.

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