Hi all,
I have a theoretical question about the error in Abaqus "The ratio of deformation speed to wave speed exceeds 1.000 in more than one element".
Take a second look at this message I found it no difference from the error "# elements were distorted excessively." Because they both indicates the time increment exceeds 1.000
The time increment is computed by deltaT = 2/omegaMax, where omegaMax is the largest natural frequency of the structure.
deltaT can be estimated by deltaT = L_min/Cd as well, where L_min is the smallest element dimension and Cd is the dilatational wave speed.
So "The ratio of deformation speed to wave speed exceeds 1.000 in more than one element" can be understood as "the ratio L_min/Cd = deltaT exceeds 1" ? Abaqus recognized time increment is too big and abort.
So regardless of model accuracy, if I increase the "Cd" assignment or make the material stiffer (so that it deforms slower), I can possibly solve the numerical error "The ratio of deformation speed to wave speed exceeds 1.000 in more than one element"...
Does the above make sense? Or is there another reason causing this error message? I apologize if the equations look cluster, I only know how to insert linear forms at this time.
Any comments will be extremely helpful, thank you very much.
S
I have a theoretical question about the error in Abaqus "The ratio of deformation speed to wave speed exceeds 1.000 in more than one element".
Take a second look at this message I found it no difference from the error "# elements were distorted excessively." Because they both indicates the time increment exceeds 1.000
The time increment is computed by deltaT = 2/omegaMax, where omegaMax is the largest natural frequency of the structure.
deltaT can be estimated by deltaT = L_min/Cd as well, where L_min is the smallest element dimension and Cd is the dilatational wave speed.
So "The ratio of deformation speed to wave speed exceeds 1.000 in more than one element" can be understood as "the ratio L_min/Cd = deltaT exceeds 1" ? Abaqus recognized time increment is too big and abort.
So regardless of model accuracy, if I increase the "Cd" assignment or make the material stiffer (so that it deforms slower), I can possibly solve the numerical error "The ratio of deformation speed to wave speed exceeds 1.000 in more than one element"...
Does the above make sense? Or is there another reason causing this error message? I apologize if the equations look cluster, I only know how to insert linear forms at this time.
Any comments will be extremely helpful, thank you very much.
S