静不定问题 meaning in English

static indeterminate problem

The portal frame is a hyper static structure , if it is analyzed by material - strength method , it is complex and large simplification must be made , and calculation accuracy is lower . larger safety - factor is often adopted to ensure the portal frame safe , this results in large structure size , more material cost and higher manufacture cost
该门架结构是一个高次静不定问题，采用传统的材料力学方法很难求得解析解，且要想求解需对结构作较大的简化，造成计算结果误差大，为此，常采用加大安全系数的方法以保证结构的安全可靠运行，结果使结构尺寸加大，浪费材料，增加制造成本。