Hello Sir, I don't understand how to get the fracture energy. Is it just the are under the curve ? And which curve are you using for your calculus ? Only the tensile curve or the pull-off and shear curves? Thank you
Hello Sir, Can you tell me or create a new video? How do you find the data E/Enn=50, G1/Ess=50, G2/Ett=50 and other data from the stress vs displacement graph ? And here data is N, mm or Ib, in or m which unit? Thank you
May I know how did you find the maximum nominal stress and slope from your plot, are those values different from the plot Great Work by the way, super videos!!
From the plot you can have an 'estimate' of nominal stress and slope. If you use a slope 10-50 times larger than the young's modulus of the material (or the young's modulus of the substrates next to interface for laminates) the numerical convergence can be achieved easily without effecting the simulation result. Note that slope has minor effect of the cohesive zone response. Maximum stress of the stress-displacement plot can be used for nominal stress. In practice, local maximum is higher than that you calculate from tensile test machine response (global response) due to necking. Eventually, we need to do trial and error using cohesive parameters we estimate from curve until the output; for example force-displacement response from experiment, is close to simulation response. If ideally we could measure local stress-response near failure zone accurately, we could avoid trial and error.
@@10Minuters Thank you for the helpful response, I've tried to send you an email with my file on a convergence issue, I'm facing. If it's possible, please look into it on anything i'm setting up wrong. THank you so much
@@aathiraja2056 I will suggest you to try with changing the cohesive material stiffness to 50 times larger than the value you are currently using and again try with 50 times lower. See if any of these help with convergence. You can next try using 5 times higher and lower interfacial strength. If you find any of these are causing the problem, adjust them in a way that fracturing energy remains unchanged.
Knn etc can be chosen arbitrarily as this has less effect of the simulation response. However, if these values are not within reasonable bounds, it can cause numerical error or very long simulation time. A good practice is to use Knn etc 10 times larger than the Young's modulus of substrate (adjacent) material.
very goof videos , please keep the good work
Hello Sir,
I don't understand how to get the fracture energy. Is it just the are under the curve ? And which curve are you using for your calculus ? Only the tensile curve or the pull-off and shear curves?
Thank you
Hello,
Can you share us some reference paper of this kind of calculation or analysis?
Thank you in advance! :)
Hello Sir,
Can you tell me or create a new video? How do you find the data E/Enn=50, G1/Ess=50, G2/Ett=50 and other data from the stress vs displacement graph ? And here data is N, mm or Ib, in or m which unit?
Thank you
May I know how did you find the maximum nominal stress and slope from your plot, are those values different from the plot Great Work by the way, super videos!!
From the plot you can have an 'estimate' of nominal stress and slope. If you use a slope 10-50 times larger than the young's modulus of the material (or the young's modulus of the substrates next to interface for laminates) the numerical convergence can be achieved easily without effecting the simulation result. Note that slope has minor effect of the cohesive zone response. Maximum stress of the stress-displacement plot can be used for nominal stress. In practice, local maximum is higher than that you calculate from tensile test machine response (global response) due to necking. Eventually, we need to do trial and error using cohesive parameters we estimate from curve until the output; for example force-displacement response from experiment, is close to simulation response. If ideally we could measure local stress-response near failure zone accurately, we could avoid trial and error.
@@10Minuters Thank you for the helpful response, I've tried to send you an email with my file on a convergence issue, I'm facing. If it's possible, please look into it on anything i'm setting up wrong. THank you so much
@@aathiraja2056 I will suggest you to try with changing the cohesive material stiffness to 50 times larger than the value you are currently using and again try with 50 times lower. See if any of these help with convergence. You can next try using 5 times higher and lower interfacial strength. If you find any of these are causing the problem, adjust them in a way that fracturing energy remains unchanged.
@@10Minuters Thank you
how to define Knn, Kss, and Ktt Sir?
Knn etc can be chosen arbitrarily as this has less effect of the simulation response. However, if these values are not within reasonable bounds, it can cause numerical error or very long simulation time. A good practice is to use Knn etc 10 times larger than the Young's modulus of substrate (adjacent) material.
@@10Minuters Thank you for your answer. However, I am still not sure, what parameters most influence debonding in the cohesive surface model?
@@ridhosurahman8461 The most important parameter is fracture energy. 2nd is the nominal stresses.
@@10Minuters I see. Thank you very much for your kind support. I really appreciate it.