patran模拟缆绳疑问

tianjian

目标：想用mpc来模拟缆绳
案例：如图，燃烧臂，竖直方向和水平方向各2根缆绳。（风从0-135度方向）
约束：支座1234，水平缆绳12，竖直缆绳13。中间用4个mpc让缆绳的结点跟truss的joint起来，（水平连接点12joint，竖直13joint）
问题：始终提示error e5001. 一个结构点rot6 奇异
如果支座修改约束为123456，可以运算，不过结构变形巨大，mpc明显实效，请问该如何施加约束？

sunnygu

FATAL ERROR: E5001: NON-POSITIVE DEFINITE DETECTED AT GRID id COMPONENT n

CAUSE
A negative term has been detected on the stiffness matrix factor diagonal during decomposition.

RESOLUTION
Investigate the degree of freedom at which the Non-Positive Definite condition occurred. Also, check the Solution Processor output in the Model Results Output File for degrees of freedom with large factor diagonal ratios. A large factor diagonal ratio may indicate a mechanism. Also, check your model for isolated large stiffnesses or too few constraints. If using shell elements, either set the model parameter, K6ROT, to a value between 1.0 and 100.0, or set the parameter, SHELLRNODE, to ON. If this does not solve the problem or you are unable to locate the source of the Non-Positive Definite, consider setting the model parameter, SOLUTIONERROR, to ON. Note that solution accuracy may be degraded with this parameter set to ON. Check the EPSILON value in the Model Results Output or Results Summary File. Values greater than 0.001 indicate a possible loss of accuracy.

hhhppp

楼主最后怎么解决的啊

卡兹斑

学习一下，谢谢分享!