Explicit Dynamic

[seaw]

Could anybody tell me briefly what is explicit dynamic?

Thanks.

 

[BASSAMSAAD]

Dear friend:

Explicit method is a numerical tool based on finite difference method for solving the set of equilibrium equations governing the engineering response of a structure under dynamic exicitation (particularly impact load of short time duration like "Blasting load&quotIt is superior to other tools(implict or modal superposition) when your system is rich in high natural frequencies and when you have large number of DOFS.

Regards,
BASSAM

 

[sden]

Further it may be of advantage to use an explicit dynamics code if you´re dealing with large deformations, complicated contact problems - high nonlinearities. In this highly nonlinear cases extremely small time steps respectively load steps are needed if you use a `standard fe code` so that the computational expense is very high. Also convergence is hard to achieve, as either the matrices are bad conditioned or the contact region changes within the iterations necessary for nonlinear solution methods. Then the standard Newton type methods loose their capability of quadratic convergence with rather large load steps.
Even so this is not the main task of this codes as their superior field is as mentioned above the field of short time impacts like crash tests....

regards
Sebastian