H. Y. Jing
,
L. X. Huo
,
Y. F. Zhang and F. Minami( 1) College of Material Science
,
Tianjin University
,
Tianjin 300072
,
China 2) Osaka University
,
Japan)
金属学报(英文版)
A computation framework for brittle fracture which incorporates weakest link statistics and a microme- chanics model reflecting reflecting local damage of the material is described.The Weibull stress W emerges as a probabilistic fracture parameter to define the condition leading material failure. Unstable crack propa- gation occurs at a critical value of W which may be attained paior to or following some amount of duc- tile crack extension. A realistic model of ductile crack growth using the computation cell methodology is used to define the evolution of near tip stress fields during crack extension. An application of proposed framework to predict the measured geometry and ductile tearing effects on the statistical distributio of fracture toughness for the pipe line steel welded joint is described.
关键词:
fracture toughness
,
null
,
null
X. Q. Yang
,
L. X. Huo
,
Y. F. Zhang and J. X. Yan (School of Material Science and Engineering
,
Tianjin University
,
Tianjin 300072
,
China)
金属学报(英文版)
The buckling formation and influence factors during welding thin - plated structures were investigated based on finite element methods, An engineering treatment method for prdicating the buckling distor- tion was proposed in here. It was used the equivalent applied thermal - load to simulate the welding residual stress,therefore the calculation of complex welding distoriton can be transformed into 3D elas- tic structural applied- load analyses, which can reduce the quantities of calculating works effectively. The validation of the method was verified by comparison of the numerical simulation and experimental results. The simulation of buckling distorition for side - walled structrues of paseenger train was per- formed and the calculation was in agreement with measuring results in general. It was shown that the main factors for producing the buckling were the intermittent fillet and ping the during welding the stiffened beams and columns to the panel.The existence of the free edge of panels would reduce the crit- ical buckling stress and enlarge the deflection obviously,but the continuous weld in closed frames didn' t degrade the buckling situation.
关键词:
welding buckling distortion
,
null
,
null
