FATAL:second_order_eqn: Complex roots. when moving active surface.

Post Reply
begumemte1991
Posts: 33
Joined: Mon May 04, 2020 8:19 am

FATAL:second_order_eqn: Complex roots. when moving active surface.

Post by begumemte1991 » Sun Mar 26, 2023 9:34 pm

Dear Team STKO,

What is the meaning of the following error:
"FATAL:second_order_eqn: Complex roots.
when moving active surface.
B2=8.34901e-23 4AC=9.37715e-23"?

NB: I am conducting a ground response analysis under seismic loading.

ValentinaSB
Posts: 61
Joined: Thu Dec 09, 2021 10:53 am

Re: FATAL:second_order_eqn: Complex roots. when moving active surface.

Post by ValentinaSB » Tue Mar 28, 2023 4:44 pm

Hi,
This error means that OpenSees is not able to solve the second-order equation somewhere in the model, that B^2 - 4*A*C is negative. There are could be different reasons that could lead to this numerical problem, for example, improper input parameters. Make sure that the parameters that you are using are correct for the PDMY(PIMY)material.

Best wishes,
Valentina

Post Reply