A steel cylinder 12 inches outside and a wall thickness of 1 in. is filled with concrete and used as a pier to support an axial load in compression If the allowable stress are 40,000 psi for steel and 3,500 psi for concrete and the youns modulus for steel is 30 x 106 psi and for concrete is 2.8 x 106 psi, what is the allowable load on the pier?
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A beam has the cross section shown in the figure below. It is subjected to a normal tensile force P whose line of action passes through the maximum allowable value of P if the maximum direct stress is limited to ± 150 N/mm2
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Two 15 N weights A and B are connected by a massless string hanging over a smooth, frictionless peg. If a third weight of 15 N is added to A and the system is released, by how much is the force on the peg increased?
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A thin walled cylindrical shell has an internal diameter of 2m. and is fabricated from plates 20mm thick. Calculate the safe pressure in the shell if the tensile strength of the plate is 400 kN/mm2 and the factor of safety is 6.
Solution:
A steel cylinder 12 inches outside and a wall thickness of 1 in. is filled with concrete and used as a pier to support an axial load in compression If the allowable stress are 40,000 psi for steel and 3,500 psi for concrete and the youns modulus for steel is 30 x 106 psi and for concrete is 2.8 x 106 psi, what is the allowable load on the pier?
Solution:
Determine the horizontal deflection of joint C of the frame shown below. Disregard the contribution of axial and shear deformation to deflection. You may use the integration equation: Integral from 0 to L of (mM) dx = 1/3 m1 M1 L and integral from 0 to L of (mM) dx = 5/12 m2 M2 L.
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Using USD or ultimate strength design method, design a simple supported reinforced concrete beam 0.20m. wide and 4.50m. long carrying only a wall load of 8.27 kN/m including its own weight. Keep the steel ratio within 1% and use 16mm dia. Reinforcing bars. Use fy = 413.7 MPa and fc’ = 27.6 MPa and a min. concrete cover of 63.5mm. Indicate the depth and number of reinforcing bars on the figure below.
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A pre-stress rectangular beam 0.50m x 0.75m has a simple span of 3m and is loaded by a uniform load of 45 kN/m including its own weight. The pre-stressing tendon is 0.225m. from the bottom and produces and effective pre-stress of 1,600 kN. Compute the total stresses of the pre-stressed beam shown.
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Determine the maximum stress in the fastener ( 7/8’ a 325 bolts) for the bearing type connection with threads in the shear plane to support the eccentrically loaded column bracket. (Fv = 21 ksi, 144 MPa). Assume that the bracket is thick enough to carry the load. Show the force and the direction on the diagram below.
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The hollow steel shaft (G = 12 x 106 psi) must transmit a torque of 300,000 in-lb. The total angle of twist must not exceed 3°per 100ft The maximum shearing strength must not exceed 16,000 psi. Find the inside diameter d if the outside diameter is equal to 12”
Solution:
Design a welded connection to sustain the design tensile strength of a double angle diagonal truss member consisting of two (2) angles 5” x 3 1/2° x 7/16 subjected to a total forced of 190 kips (847.88 kN). A 558 steel is used (fy = 50 ksi, 344.82 MPa), using 1/4° fillet weld and E 70 electrodes. Area of one angle is 3.53 sq.in. and the centroid is 1.63” from the smaller leg.
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A precast concrete beam of length L is to be lifted from the casting bed and transported so that the maximum bending moment is as small as possible. If the beam is to be lifted by two slings, at what distance d from the ends should the slings be attached?
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An object is place 3 ft. from the center of a horizontally rotating platform. The coefficient of friction is 0.30. The object will begin to slide off when the platform speed is nearest to.
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A pendulum with a concentrated mass “m” is suspended vertically inside a stationary railroad freight car by means of a rigid weightless connecting rod. If the connecting rod is pivoted where it is attached to the box car, compute the angle that the rod makes with the vertical as a result of a constant horizontal acceleration of 2 feet/sec2 of the box car.
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A body moves so that during the first part of its motion, its distance S in meters from the starting point is given by the expression: S = 6.8 t3 – 10.8 t. The acceleration in 3 seconds is:
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An airtight closed box of weight P is suspended from a spring balance. A bird of weight W is placed on the floor of the box, and the balance reads W + P. If the bird flies around in the box at a constant elevation without accelerating, what is the balance reading?
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The figure below shows a beam ABCD supporting three concentrated loads two of which are inclined to the longitudinal axis of the beam. What is the value of the largest normal (axial) force?
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The coefficient of friction between the 60 kN block and the plane shown is 0.30. If the block is to remain in equilibrium, what is the maximum allowable magnitude for the force P?
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Two circular shafts, one hollow and one solid, are made of the same material and have the diameters shown below. If Th is the twisting moment that the hollow shaft can resist and Ts is the twisting moment that the solid shaft can resist, the ratio of Th to Ts is:
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The magnitude of the force acting in the member BC of the truss shown below is:
Solution:
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