Submitted by Nguyen Van Chau on Sun, 11/18/2007 - 01:00 Dynamic J-integral are independent path 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 damoonmoetamedi 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 ? Log in or register to post comments Sun, 12/09/2007 - 16:10 Permalink Nguyen Van Chau In reply to How do you calculate J-integ by damoonmoetamedi 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 Log in or register to post comments Mon, 12/10/2007 - 02:01 Permalink damoonmoetamedi 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 Log in or register to post comments Mon, 12/10/2007 - 03:29 Permalink Nguyen Van Chau In reply to thanks, but still I dont get it by damoonmoetamedi U can read Newmark U can read Newmark method... Log in or register to post comments Mon, 12/10/2007 - 03:49 Permalink damoonmoetamedi 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)? Log in or register to post comments Mon, 12/10/2007 - 06:10 Permalink Log in or register to post comments9300 views
damoonmoetamedi 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 ? Log in or register to post comments Sun, 12/09/2007 - 16:10 Permalink
Nguyen Van Chau In reply to How do you calculate J-integ by damoonmoetamedi 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 Log in or register to post comments Mon, 12/10/2007 - 02:01 Permalink
damoonmoetamedi 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 Log in or register to post comments Mon, 12/10/2007 - 03:29 Permalink
Nguyen Van Chau In reply to thanks, but still I dont get it by damoonmoetamedi U can read Newmark U can read Newmark method... Log in or register to post comments Mon, 12/10/2007 - 03:49 Permalink
damoonmoetamedi 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)? Log in or register to post comments Mon, 12/10/2007 - 06:10 Permalink
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 ?
In reply to How do you calculate J-integ by damoonmoetamedi
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
In reply to thanks, but still I dont get it by damoonmoetamedi
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)?