Constitutive Integration Algorithm of Crystal Thermal Deformation

Author(s):  
Ping Hu ◽  
Liang Ying ◽  
Bin He
2002 ◽  
Vol 12 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Feng Sun ◽  
Wenfeng Yu ◽  
Zuhai Cheng ◽  
Yaoning Zhang

Author(s):  
A.C.T. Quah ◽  
J.C.H. Phang ◽  
L.S. Koh ◽  
S.H. Tan ◽  
C.M. Chua

Abstract This paper describes a pulsed laser induced digital signal integration algorithm for pulsed laser operation that is compatible with existing ac-coupled and dc-coupled detection systems for fault localization. This algorithm enhances laser induced detection sensitivity without a lock-in amplifier. The best detection sensitivity is achieved at a pulsing frequency range between 500 Hz to 1.5 kHz. Within this frequency range, the algorithm is capable of achieving more than 9 times enhancement in detection sensitivity.


2020 ◽  
Vol 56 (22) ◽  
pp. 1208-1210
Author(s):  
Wenchao Yu ◽  
Weimin Su ◽  
Hong Gu ◽  
Jianchao Yang ◽  
Xingyu Lu

2021 ◽  
Vol 11 (12) ◽  
pp. 5509
Author(s):  
Hongjin Choi ◽  
Seonghwan Choi ◽  
Soo-Chang Kang ◽  
Myoung-Gyu Lee

A fully implicit stress integration algorithm is developed for the distortional hardening model, namely the e−HAH model, capable of simulating cross−hardening/softening under orthogonal loading path changes. The implicit algorithm solves a complete set of residuals as nonlinear functions of stress, a microstructure deviator, and plastic state variables of the constitutive model, and provides a consistent tangent modulus. The number of residuals is set to be 20 or 14 for the continuum or shell elements, respectively. Comprehensive comparison programs are presented regarding the predictive accuracy and stability with different numerical algorithms, strain increments, material properties, and loading conditions. The flow stress and r−value evolutions under reverse/cross−loading conditions prove that the algorithm is robust and accurate, even with large strain increments. By contrast, the cutting−plane method and partially implicit Euler backward method, which are characterized by a reduced number of residuals, result in unstable responses under abrupt loading path changes. Finally, the algorithm is implemented into the finite element modeling of large−size, S−rail forming and the springback for two automotive steel sheets, which is often solved by a hybrid dynamic explicit–implicit scheme. The fully implicit algorithm performs well for the whole simulation with the solely static implicit scheme.


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