What are the most unfavorable arrangements for vertical loads in frame design?
1. Crossover combination method The active load is applied to the structure layer by layer, and the internal forces of the whole structure are calculated separately. The most unfavorable internal force is composed according to different components, different sections and different internal forces. In order to reduce the computational workload, consider taking into account the live load of the roof. 2. The most unfavorable load position method In order to find the most unfavorable internal force of a given section, the live load arrangement that produces the most unfavorable internal force can be directly determined according to the influence line method. If you want the most unfavorable arrangement of the live load of the maximum positive bending moment MC of the cross-section C of a span beam AB, you can first make the influence line of the MC, that is, release the corresponding constraint (change the point C to the hinge) and replace it with the positive constraint. The force ...