Question

Consider the rectangular beam shown below 25 kN/m 10 kN 0.2 m 0.2 m 0.5 m 1 m (10pts) Find the critical location or segment of the beam where stresses will be maximum. (10pts) The beam has a square cross section with a side of 25mm. Find the principal stresses at the top or bottom of the cross section, at the location or segment found in point 2 (10pts) The beam is made of 52100 chromium steel, with a yield strength of 2070 MPa and a modulus of 207 GPa. Using the maximum distortion energy theory, find the factor of safety for this design. (20pts) Before deploying this beam for operation, you are tasked with inspecting it for cracks Typical minimum sizes detected by several inspection methods are provided below [Callister, 8ed] Since the beam is large, only the dye penetrant technique is deemed practical for this inspection Assuming a worst-case scenario i.e. the largest potential crack is not detected, find the factor of safet 2. 3. 4. 5. Table 8.2 A List of Several Common Nondestructive Testing (NDT) Techniques Defect Size Sensitivity (mm) Technique Scanning electron Testing Location Laboratory Defect Location Surface 0.001 microscopy (SEM) Dye penetrant Ultrasonics Optical microscopy Visual inspection Acoustic emission Radiography Surface Subsurface Surface Surface Laboratory in-field Laboratorv/in-field Laboratory Laboratory in-field Laboratory/in-field Laboratory/in-field 0.025-0.25 >0.050 0.1-0.5 0.1 Surface/subsurface >0.1 Subsurface >2% of specimen (x-ray/gamma ray) thickness

Answer 1

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