2016 07 22

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Exercise 2. The assessment formula for the bolts, according to CNR UNI 10011 standard, is: ቀ஢ ஢౗ౚౣ ቁଶ +ቀத த౗ౚౣ ቁଶ ≤1 (1) a. Discuss for which loading condition it is acceptable to use equation (1). b. Demonstrate that this formula is consistent with the failure criteria for ductile materials. Master of Science in Mechanical Engineering Politecnico di Milano Course of Machine Design 2 (Prof. S. Beretta, Prof. M. Giglio, Prof.ssa L. Vergani) Written test – 22.07.2016 Name: Surname: Polimi-ID: Do not write here 1 2 3 4 TOTAL Exercise 1. Figure 1 shows a pipeline for fluid transport, with a series of supports. Consider the pipeline as infinitely long. Loads applied to the pipeline are: 1) p, the inner pressure of the fluid and 2) q, the distributed weight. The pipeline has a circular cross section with inner diameter di and outer diameter de. It is requested to: a. Evaluate the bending moments between each span and plot the diagram of the bending moment; b. Perform the static assessment of the pipeline at the most stressed point of the most stressed section. Consider pmax=2∙p; c. Perform the fatigue assessment of the pipeline at the centre of the span, at the inner wall. Consider that the inner pressure is pulsating from zero to p. Figure 1 – Scheme of the pipeline. p = 5 MPa inner pressure of the fluid q = 2 N/mm weight per unit length of the pipeline L = 10 m span between supports Material: steel (UTS = 600 MPa; YS = 450 MPa) di = 120 mm inner diameter of the pipeline de = 130 mm outer diameter of the pipeline L L L q p Master of Science in Mechanical Engineering Politecnico di Milano Course of Machine Design 2 (Prof. S. Beretta, Prof. M. Giglio, Prof.ssa L. Vergani) Written test – 22.07.2016 Name: Surname: Polimi-ID: Exercise 3. It is required to verify the safety of…