Combined loading

Stress and Distortion. The forces acting on a stmcture are transmitted through the welded joints that is, the joint is subjected to simple tension (or compression), bending, shear, or torsional stresses, or to combinations of these stresses owing to combined loading situations. Weldments must be of a proper size, length, and location to withstand the loads imposed during service. 

The designer must have a full appreciation of load combinations, load paths, primary and secondary effects on stmctural elements, and the relative flexibihty of the elements. Special attention must be given to how the most critical details in the stmcture are to be constmcted so that the full requirements and intent of the design can be realized (10). 

S. Cheng and B. P. C. Ho, Stability of Heterogeneous Aeolotropic Cylindrical Shells under Combined Loading, AIAA Journal, April 1963, pp. 892-898. 

Foundation Loads and Pressures. Foundations should be designed to support the weight of the structure, the live load, and the load effect on the structure and its foundation due to such other loads as v. ind. In general, for foundation designs, a safety factor of 3 is used for dead loads or live loads independently. A safety factor of 2 is used for combination loads including transient loads [38,40]. 

Maximum rated combined load of setback and rotary table beams. 

An extension to this is to install two boilers, each capable of handling the total combined load. Depending upon the boiler size, there may be only a relatively small difference in total capital cost between the above two schemes. 

Pressure vessels are subjected to other loads in addition to pressure (see Section 13.4.7) and must be designed to withstand the worst combination of loading without failure It is not practical to give an explicit relationship for the vessel thickness to resist combined loads. A trial thickness must be assumed (based on that calculated for pressure alone) and the resultant stress from all loads determined to ensure that the maximum allowable stress intensity is not exceeded at any point. 

Figure 13.17. Stresses in a cylindrical shell under combined loading...

---