Question

Please help with detail and good handwriting for all parts. Thank you. (Mechanical Properties of Materials)

1.2 Repeat Prob. 1.1 for the following failures: (a) A child's plastic tricycle develops cracks where the handlebars join the frame. (b) An aluminum baseball bat develops a crack. (c) A large steel artillery tube (barrel), which previously had cracks emanating from the rifling, suddenly bursts into pieces. Classify both the cracks and the final fracture. (Problem continues)

Answer 1

ANSWER:
Given that . The cracks in the handlebars one the result of low cycle fatigue. The handle bans have likely been subjected to extreme loads for a few hundred loading cycles. low cycle fatigue is often accompanied by large de formations and must be analyzed in a different manner than high cycle fatigue. . The crack is the result of low cycle fatigue. The about was likely designed for less than a hundred extreme loading cycles daily. The cracks formed because of low cycle fatigue. Artillery barrels are designed for a daily average of less than a hundred firings, though these firing induce high stresses on the components once cracks were present fatigue erack growth ultimately led to failure by brittle fracture when the barrel suddenly broke a part

The cracks formed due to high cycle fatigue The fuselag of an ahcraft with stands constantly changing internal and external pressures, Occurring hundreds of thousands of troses during the course of each flight. stresses were apparently highest t the corners of windows, So, cracks appeared here. Then fatigue. crack growt' caused them to extend to the entire fuselage until the joined causing it to come apart Since aluminiuion Po ä generally ductive material and space the loading was not. Sudden (impact loading failure was likely was likely a ductile fracture. The turbine blades increased length as a result of creep. The high temperatures and the constant roading are ideal. conditions for creep to occur. The casing undergoes wear when the lengthened blades repeateadly sub against it, mechanically coupog.loss of material. I