請(qǐng)問(wèn)一下，在使用abaqus進(jìn)行模擬時(shí)，warnings這部分出現(xiàn)了There is zero PR. FLUX everywhere in the model based on the default criterion. please check the value of the average PR. FLUX during the current iteration to verify that the PR. FLUX is small enough to be treated as zero. if not, please use the solution controls to reset the criterion for zero PR. FLUX. 這是是那么原因造成的，該怎么解決呢