Required information For a bolted assembly with 19 bolts, the stiffness of each bolt is kh= 1.0 MN/mm and the stiffness of the members is km %3D 2.6 MN/mm per bolt. The bolts are preloaded to 75 percent of proof stiffness. Assume the external load is equally distributed to all bolts. The bolts are M6 x 1 class 5.8 with rolled threads. A fluctuating load is applied to the entire joint with Wmax = 60 kN and Wmin = 20 kN. The bolt diameter is d= 6 mm.
Design Against Fluctuating Loads
Machine elements are subjected to varieties of loads, some components are subjected to static loads, while some machine components are subjected to fluctuating loads, whose load magnitude tends to fluctuate. The components of a machine, when rotating at a high speed, are subjected to a high degree of load, which fluctuates from a high value to a low value. For the machine elements under the action of static loads, static failure theories are applied to know the safe and hazardous working conditions and regions. However, most of the machine elements are subjected to variable or fluctuating stresses, due to the nature of load that fluctuates from high magnitude to low magnitude. Also, the nature of the loads is repetitive. For instance, shafts, bearings, cams and followers, and so on.
Design Against Fluctuating Load
Stress is defined as force per unit area. When there is localization of huge stresses in mechanical components, due to irregularities present in components and sudden changes in cross-section is known as stress concentration. For example, groves, keyways, screw threads, oil holes, splines etc. are irregularities.
Find the yielding factor of safety (np) , the overload factor of safety, factor of safety based on joint seperation, and fatigue factor using goodman criterion..
Thank you! in advance
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 2 images
