Question Two solid cylindrical rods AB and BC

Question Two solid cylindrical rods AB and BC are welded together at B and loaded as shown in figure. Knowing that d 1 =50 mm and d 2 = 30 mm, find the average normal stress at the midsection of (i) Rod AB, (ii) Rod BC. 1 Jump to first page

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Question Two solid cylindrical rods AB and BC are welded together at B and loaded as shown in figure. Knowing that the average normal stress must not exceed 140 Mpa in either rod, determine the smallest allowable values of d 1 and d 2. 3 Jump to first page

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Two solid cylindrical rods AB and BC are welded together at B and loaded as shown. Determine the average normal stress at the midsection of (i) Rod AB, (ii) Rod BC. 5 Jump to first page

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When the force P reached 8 KN, the wooden specimen shown failed in shear along the surface by the dashed line. Determine the average shearing stress along the surface at the time of failure. 7 Jump to first page

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The wooden members A and B are to be joined by plywood splice plates which will be fully glued on the surface in contact. As part of the design of the joint, and knowing that the clearance between the ends of the members is to be ¼ in, determine the smallest allowable length L if the average shearing stress in the glue is not to exceed 120 psi. 9 Jump to first page

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A load P is applied to a steel rod supported as shown by an aluminum plate into which a 0. 6 in diameter hole has been drilled. Knowing that the shearing stress must not exceed 18 Ksi in the steel rod and 10 Ksi in the aluminum plate. Determine the largest load P that may be applied to the rod. 12 Jump to first page

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ALLOWABLE STRESS n n n When designing a structural member or mechanical element, the stress in it must be restricted to safe level Choose an allowable load that is less than the load the member can fully support One method used is the factor of safety (F. S. ) Ffail F. S. = Fallow 14 Jump to first page

ALLOWABLE STRESS If load applied is linearly related to stress developed within member, then F. S. can also be expressed as: n σfail F. S. = σ allow • • 15 τfail F. S. = τ allow In all the equations, F. S. is chosen to be greater than 1, to avoid potential for failure Specific values will depend on types of material used and its intended purpose Jump to first page

In the structure shown, an 8 mm diameter pin is used at A, and 12 mm diameter pins are used at B and D. Knowing that the ultimate shearing stress is 100 Mpa at all connections and the ultimate normal stress is 250 Mpa in each of the two links joining B and D. Determine the allowable load P, if an overall fctor of safety of 3. 0 is desired. Top View 16 Side View Front View Jump to first page

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Poisson's ratio : For a homogeneous isotropic material d F F x n normal strain : lateral strain : Poisson's ratio : 19 Jump to first page