I am trying to implement periodic boundary in a 3D RVE using dummy_nodes. My goal is found the coefficients of the elastic tensor, I am successfully getting the values for the coefficients C11, C22, C33, C44, C55 and C66. I perform three independent simulations 3 axial loadings and 3 shear loadings. For example, for the axial loading in x-direction, I impose a displacement in the direction x in the dummy_node_x that represents the average strain divided to the RVE length. After find the average stress with the strain energy relation (U=0.5*V*average_strain(x)*average_stress(x)) I obtain the C11 value.
However, I am not seen how can I found the value of the coefficient C12 that should be equal to average_stress_x divided to the averge_strain_y. But i am not able to find the value of the average_strain_y using the dummy_node_x degrees of freedom.

Did you get your problem resolved? Is there a reason you want to find the properties by using a strain energy relation? You should be able to find the effective stiffness as described in the attachment from Dr. Yu’s book. Let me know what you think.

pedro carneiro@ onI am trying to implement periodic boundary in a 3D RVE using dummy_nodes. My goal is found the coefficients of the elastic tensor, I am successfully getting the values for the coefficients C11, C22, C33, C44, C55 and C66. I perform three independent simulations 3 axial loadings and 3 shear loadings. For example, for the axial loading in x-direction, I impose a displacement in the direction x in the dummy_node_x that represents the average strain divided to the RVE length. After find the average stress with the strain energy relation (U=0.5*V*average_strain(x)*average_stress(x)) I obtain the C11 value.

However, I am not seen how can I found the value of the coefficient C12 that should be equal to average_stress_x divided to the averge_strain_y. But i am not able to find the value of the average_strain_y using the dummy_node_x degrees of freedom.

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Ernesto Camarena@ onDid you get your problem resolved? Is there a reason you want to find the properties by using a strain energy relation? You should be able to find the effective stiffness as described in the attachment from Dr. Yu’s book. Let me know what you think.

Pages-from-Prof.-Yu-Book-PBCs.pdf

73 KBClick to download

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