A specimen of a ceramic material having an elastic modulus of 250 GPa (36.3 x 106 psi) is pulled in tension with a stress of 750 MPa (109,000 psi). Will the specimen fail if its “most severe flaw” is an internal crack that has a length of 0.20 mm (7.87 x 10-3 in.) and a tip radius of curvature of 0.001 mm (3.94 x 10-5 in.)? Why or why not?

A specimen of a ceramic material having an elastic modulus of 250 GPa (36.3 x 106 psi) is pulled in tension with a stress of 750 MPa (109,000 psi). Will the specimen fail if its “most severe flaw” is an internal crack that has a length of 0.20 mm (7.87 x 10-3 in.) and a tip radius of curvature of 0.001 mm (3.94 x 10-5 in.)? Why or why not?

Welding: Principles and Applications (MindTap Course List)

8th Edition

ISBN:9781305494695

Author:Larry Jeffus

Publisher:Larry Jeffus

Chapter25: Testing And Inspection

Section: Chapter Questions

Problem 29R: Why are guidelines drawn on the surface of a free-bend specimen?

See similar textbooks

Similar questions

Why are guidelines drawn on the surface of a free-bend specimen?
Given your understanding of what initiates and controls failure in materials, which of the following will increase the failure strength or lifetime of a test piece or component and why? a. Increasing the grain size so there are less grain boundaries to initiate failure b. Decreasing the temperature below the brittle-ductile transition temperature, to make it harder c. Decreasing the difference between the maximum and minimum stress values, as this effects the stress concentration factor d. Polishing to reduce surface defects e. Increasing its volume, to give a larger cross sectional area
(one or more option can be true please select from below) which of the following will reduce the failure strength or lifetime of a test piece and why? Decreasing the grain size, more grain boundaries to initiate failure Raising the temperature above the BDTT, more plastic deformation in the lattice will cause it to fail faster Increasing its volume, greater likelihood of critical defects Decreasing the loading frequency, the material will be at peak stress values for longer Increasing the difference between the maximum and minimum stress values, as this affects the stress concentration factor
Check the incorrect statements. a) As the thickness of the specimen increases, the fracture toughness decreases. b) Hardening a material results in an increase in fracture toughness. c) Larger defects reduce the allowable stress on a mechanical component. d) Increasing temperature usually decreases fracture toughness. e) Eliminating impurities in molten metal and special powder metallurgy techniques that favor the densification of ceramics and metal alloys impair fracture toughness.
A crack has been discovered along the edge of a reinforcing rib in titanium housing. The rib is 0.5 inches thick and 4.0 inches wide. The crack extends completely through the thickness and is about 1.20 inches long. If the housing is subjected to static loading only, and the maximumestimated loading produces a tensile load along the rib axis of 50,000 Ib, should the housing be removed from service? The housing material exhibits a yield strength of 150 ksi and a plane strain fracture toughness of 50 ksi in1/2.
You are called as an expert witness to analyze the fracture of a sintered silicon carbide plate that was fractured in bending when a blunt load was applied to the plate center. Measurement of the distance between the fracture origin and the mirror/mist boundary on the fracture surface gives a radius of 0.796 mm. You are given three pieces of the same SiC to test, and you determine that the mirror radius is 0.603, 0.203, and 0.162 mm for bending failure stress levels of 225, 368, and 442 MPa, respectively. What is your estimate of the stress present at the time of fracture for the original plate?
Why are cracks & notches prone to fracture propagation?
What are the experimental techniques used to measure the strain?
27d) If a material of a component has a youngs modulus of elasticity of 500 GPa, what strain will be produced by a stress of 3 MPa?
6) The energy absorbed during the fracture of notched specimen is related to the area under the stress-strain curve is known as ___________. Select one: Brittleness Plasticity Toughness Hardness
You are called in to evaluate the failure of a component produced from a nickel superalloy (Inconel). The evaluator is not sure what they are looking at. You are sent the following micrograph. Educate this young engineer. a. Detail everything that you can see in terms of the characteristics of failure. b. Define if you can whether this is a ductile or brittle failure. c. Can you interpret the direction of fracture progression?
How is normal strain measured?