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Dynamic J-integral are independent path
Sat, 2007-11-17 20:00 - Nguyen Van Chau
Dear Alls;
Would you please explain for me why Dynamic J-integral increases when crack propagates, and why Dynamic J-integral are independent with difference paths.
Best Regards;
Chau
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How do you calculate J-integ
I am working on dynamic fracture problem in orthotropic media and for
finding DSIF, I have to calculate dynamic J-integral. If I use auxiliary
field there are terms related to the velocity of auxiliary displacement
and velocity of auxiliary strain, how can I calculate auxiliary
velocities?
a one paper author mentioned the separation Integral which used to find K1 and K2 in isotropic material.
Could you help me to find orthotropic formulas for separation Integral ?
Hi; The auxiliary
Hi;
The auxiliary velocities will be (u and v are velocity components)
du/dx = u_i* dN/dx * x_i,j
du/dy = u_i*dN/dy * y_i,j
so on...
N are shape functions
(x,y) is displacement component
Good luck
thanks, but still I dont get it
thanks Nguyen for your answer,
But I still dont understand how to calculate du/dt,dv/dt (u and v are auxiliary displacements) in first place.
I think you mentioned how to calculate strain velocities.
damoon
U can read Newmark
U can read Newmark method...
I know newmark method
we use auxiliary field near crack tip and some elements are involving in auxiliary calculation.
so you mean I just need to compute K and M for auxiliary field elements. Then use newmark method to find du/dt and dv/dt?
have you any example or solved problem I can read?
By the way, do you know how can I calculate DSIF in orthotropic material (formulas related to dynamic J-integ for K1 & K2)?