(25) Two specimens with the same dimensions and material were subjected to fatigue tests. The figure below describes th...
Q.3. Three identical fatigue specimens (denoted A, B, and C) are fabricated from a nonferrous alloy. Each is subjected to one of the maximum-minimum stress cycles listed in the following table; the frequency is the same for all three Specimen Omax (MPa) Omin(MPa) tests. Rank the fatigue lifetimes of A + 450 150 these three specimens from the B + 300 300 shortest to the longest. с + 500 200
Q1-D In a fatigue test, a number of specimens should be prepared from the same batch of material. Starting at comparatively high values for the magnitude of the stress reversal, cach specimen is tested to failure at a successively lower level of stress reversal. The magnitude of the stress reversal and the number of cycles to failure are recorded graphically for cach specimen. Plot the expected trend of strength versus number of cycles for mild steel material. [30 Marks] Answer...
Q6. (a) Three identical fatigue specimens (denoted A, B and C) are fabricated from a non-ferrous alloy. Each is subjected to one of the maximum- minimum stress cycles listed in Table 26 (the frequency is the same for all tests) Table 26 Specimen Omax (MPa) Omin (MPa) A +450 -150 +300 -300 +500 -200 Rank the three specimens in terms of their fatigue lifetimes (highest to lowest). Justify this ranking [5 marks] (b) A cylindrical tie rod of diameter 20...
For our fatigue experiment, the minimum diameter of the specimen is 0.25 inch. Based on the endurance limit, what is your estimation of the ultimate strength (Sw) of this material? 550 500 I 450 400 350 amplitude (MPa) 300 . 250 200 200 Stress a 150 100 50 102 107 103 104 105 106 Fatigue life (cycles) 210 MPa 420 MPa 490 MPa 540 MPa For our fatigue experiment, the minimum diameter of the specimen is 0.25 inch. If the...
eslblem 2 25 pt)oe Two triaxial compression tests are conducted on identical specimens of the same saturated clay. In the first test the soil is first consolidated to ?.-350 kPa and u.-200 kPa and then sheared under drained conditions increasing the axial stress while keeping the chamber pressure constant. At failure ?i 560 kPa. In the second test, the specimen is consolidated to ?.-600 kPa and uo-400 kPa, then it is sheared under undrained conditions increasing the axial stress while...
2. Tensile and fully reversed loading fatigue tests were conducted for a certain steel alloy and revealed the tensile strength and endurance limit to be 1200 and 550 MPa, respectively. If a rod of this material supply were subjected to a static stress of 600 MPa and oscillating stresses whose total range was 700 MPa, would you expect the rod to fail by fatigue processes? Use the Gerber relation for the analysis.
The mechanical component shown in the figure is subjected to variable loading conditions that cause the axial stresses to fluctuate as indicated in the stress-time history. The material of the part is AISI 1045 HR steel with an ultimate static strength of 570 MPa. The part has been tested in the laboratory under different completely reversed stress amplitudes, the fatigue life results of these tests are shown in the table a) The S-N diagram of the part based on the...
MEE2001/2015 Q5. A thin walled steel cylinder with 10 mm wall thickness and internal diameter of 200 mm (Fig. Q5) is subjected to an internal pressure, p. The steel used for the cylinder has a yield stress of 240 MPa. +F 200 mm Fig. Q5 (a) If a tensile axial force of 1MN is applied to the end plate, show that the maximum internal pressure that can be applied before the cylinder yields according to the Tresca criterion is 16.2...
Problem 1 Consider two Al aircraft under conditions of high cycle fatigue (HCF). Plate A will be subjected to with ƠmF-100 MPa (compression) and ƠmayR 100 MPa (tensio 0m--50 MPa (compression) and ơma.-150 MPa (tension). (a) Calculate the fatigue lives of the two plates. Based on your results, which plate replaced first? (15 points) (b) Suppose we would like to increase the fatigue life to 25.000.000 cycles, keepin amplitude constant at ơaF 100 MPa. Calculate the new values of Ơminando,...
Q.4 (25 marks) A material is subjected to two mutually perpendicular direct stresses of 300 MPa tensile and 200 MPa compressive, together with a shear stress of 50 MPa, as shown in the figure below. Use the Mohr's circle to determine: A. The principal stresses and their corresponding principal planes, B. The maximum shear stress and the planes of maximum shear stress, also C. Show the principal stresses calculated above on a sketch of the element D. Determine the state...