how can this equation be used to determine important design factors.
(Plane strain fracture toughness)
how can this equation be used to determine important design factors. (Plane strain fracture toughness) Kc...
1. A large plate is fabricated from a steel alloy that has a plane strain fracture toughness of 82.4 MPavm. If the plate is exposed to a tensile stress of 345 MPa during service use, determine the minimum length of a surface crack that will lead to fracture. Assume a value of 1.0 for Y. Maximum stress at tip of elliptically shaped crack Pt 2Ery, 1/2 critical stress required for crack propagation in a brittle material πα KIe YoeVra Fracture...
3. A structural component is fabricated from an alloy that has a plane-strain fracture toughness of 69 MPa, m (69 MPa square root of "m"). It has been determined that this component fails at a stress of 250 MPa when the maximum length of a surface crack is 1.6 mm. What is the maximum allowable surface crack length (in mm) without fracture for this same component exposed to a stress of 250 MPa and made from another alloy that has...
A specimen of a 4340 steel alloy with a plane strain fracture toughness of 54.8 MPaym (50 ksi n) is exposed to a stress of 1225 MPa (177700 psi). Assume that the parameter Y has a value of 1.04 (a) If the largest surface crack is 0.7 mm (0.02756 in.) long, determine the critical stress C- MPa (b) Will this specimen experience fracture?
A large plate is fabricated from a steel alloy that has a plane strain fracture toughness of 75 MPam (68.25 ksi vin.). If the plate is exposed to a tensile stress of 347 MPa (50330 psi) during use, determine the minimum length of a surface crack that will lead to fracture. Assume a value of 0.94 for Y. mm
dilu uucull llldlcidis. Musli dle will d ulagi dll 2. Define fracture toughness. Write the equation for fracture toughness and the mathematical and qualitative definition of all parameters. What is the difference between fracture toughness and plane strain fracture toughness?
An aircraft component is fabricated from an Al alloy that has a plane strain fracture toughness of 32 MPa·m1/2. It has been determined that fracture results at a stress of 235 MPa when the maximum internal crack length is 1.8 mm. For the same component and alloy, will fracture occur at a stress level of 310 MPa when the maximum internal crack length is 0.9 mm?
(2) Maraging steel (300 grade) has a yield strength of 2100 MPa and a plane-strain fracture toughness of 66 MPa-m1. This material is to be used for a landing gear and the maximum design stress is 70% of yield strength. If flaws must be 1.0 mm long to be detectable, is this a reasonable operating stress? Assume edge cracks and Y-1.12
2. An aircraft component is fabricated from an aluminum alloy that has a plane strain fracture toughness of 35 MPa m. It has been determined that fracture results at a stress of 250 MPa when the maximum (or critical) internal crack length is 2.0 mm. For this same component and alloy, will fracture occur at a stress level of 325 MPa when the maximum internal crack length is 1.0 mm? (10 points)
SECTION A Q1. (a) The standards for testing the fracture toughness of materials define the shape and proportion of the specimens but not their size. Explain why this is and why it is necessary to use specimens of different sizes for these tests. [5 marks] (b) You are testing samples of steel with a yield stress of 1200 MPa. Initial results show that the fracture toughness is 120 MPavm. The specimens are 10 mm thick. Determine whether the specimens are...
5. a) Explain how the tip shape amplifies the applied stress with the help of maximum stress equation and diagrams. b) Discuss plane strain fracture toughness.