What is the fatigue lifetime for this steel if the stress amplitude is 65% of the tensile strength?
What is the fatigue lifetime for this steel if the stress amplitude is 65% of the...
A large flat plate is subjected to a constant-stress-amplitude fatigue loading. Before the fatigue test, the precrack length in the material was 1.25 mm. The yield strength of this material is 300 MPa; the Young's modulus is 211 GPa; the fracture resistance (the A large flat plate is subjected to a constant-stress-amplitude fatigue loading. Before the fatigue test, the precrack length in the material was 1.25 mm. The yield strength of this material is 300 MPa; the Young's modulus is...
Need help asap b) A polished rotating-beam test specimen is made of AISI 4140 Q&T steel and the heat treated steel material has an ultimate tensile strength of 1550 MPa and yield strength of f- 0.77, estimate: 1430 MPa. Assuming the fatigue strength fraction 0) Fatigue strength corresponding to a life of 10° cycles of stress reversal (5 marks) (i) Life of the specimen if it is tested at a completely reversed stress amplitude of 400 MPa (2 marks) b)...
Need help asap b) A po lished rotating-beam test specimen is made of AISI 4340 quenched and tempered (Q&T) steel and the heat treated steel material has an ultimate tensile strength of 1470 MPa and yield strength of 1360 MPa. Assuming the fatigue strength fraction f-0.77, estimate the life of the specimen if it is tested at a completely reversed stress amplitude of 500 MPa. (7 Marks) b) A po lished rotating-beam test specimen is made of AISI 4340 quenched...
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.
(A) Describe how fatigue damage happens in a ductile material. Draw sketches if needed. (B) If we maintain a constant stress σ-0.9G (GIs the yield strength) on a steel, will fatigue damage happen? Why? (A) Describe how fatigue damage happens in a ductile material. Draw sketches if needed. (B) If we maintain a constant stress σ-0.9G (GIs the yield strength) on a steel, will fatigue damage happen? Why?
Estimating fatigue strength (Sr) of a rotating- beam specimen made of AISI 1020 hot-rolled steel corresponding to a life of 12.5(103) cycles of stress reversals. Estimate the life of the specimen corresponding to a stress amplitude (?rev-Ta) of 36 kpsi using the 1st and 2nd approach, and compare the results
The fatigue data for a ductile cast iron are given as follows: (7 pts Stress Amplitude IMPa (ksi 248 (36.0) 236 (34.2) 224 (32.5 213 (30.9) 201 (29.1) 93 (28.0) 193 (28.0 193 (28.0) Cycles to Failure I x 10 3 x 10 1 x 10 I x 107 3 x 107 3 x 10 a) Make an S-N plot (stress amplitude versus logarithm cycles to failure) using these data. b) What is the fatigue limit for this alloy? (c)...
A rotating beam made of steel has an ultimate strength of 180 kpsi. Estimate the fatigue strength corresponding to a life of 120 000 cycles of completely reversed stress.
A material with a tensile strength of 350 MPa is loaded cyclically about a mean stress of 70 MPa. If the stress range that will cause fatigue fracture in 105 cycles under zero mean stress is ±60 MPa, what stress range about the mean of 70 MPa will give the same life? (Hint: Use Goodman's relation)
The SAE 1015 steel of Table 9.1 is subjected to a stress amplitude of ?a = 160MPa. Estimate the life for mean stresses ?m of (a) zero, (b) 70 MPa tension, and (c) 70 MPa compression using: (a) Morrow equation (b) SWT equation (c) Walker equation with ? = 0.735 Chapter 9 Fatigue of Materials: Introduction and Stress-Ra Table 9.1 Constants for Stress-Life Curves for Various Ductile Engineering Metals, From Tests at Zero Mean Stress on Unnotched Axial Specimens Yield...