Recent content by smr101

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    How Do You Calculate Strain Energy in Beams Using Integral Equations?

    I'm not understand what you mean by 'squared term by term'. What terms? Again, I've noticed for the second beam doing what I did in my last post and dividing by 3 gives the correct solution.
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    Solving for y in A(total)*y(horz centroidal axis): Where Did I Go Wrong?

    Right, so the centroid, y, of the circle is just 75mm?
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    Solving for y in A(total)*y(horz centroidal axis): Where Did I Go Wrong?

    Hi, having problems with (a) here, I'll show my attempt: A1 = (0.025 * 0.05) - ((pi*0.01^2)/ 2) 1.093 x10^-3 m^2 A2 = (0.075 * 0.05) - ((pi*0.01^2)/2) = 3.593 x10^-3 m^2 A(total)*y(horz centroidal axis) = A1y1 + A2y2 y = 1.093 x10^-3 * 0.0875 + 3.593x10^-3 * 0.0375 /(4.686x10^-3) = 49.19 mm...
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    How Do You Calculate Strain Energy in Beams Using Integral Equations?

    This is what I thought would be the case, I did the following: 2EIU = M^2*s U = 400,000^2 * 4 / (2 * 200x10^9 * 60.8x10^-6) = 26.315 kJ The solution states the answer is 8.772 kJ. Which strangely enough is exactly a third of the answer I got it...
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    How Do You Calculate Strain Energy in Beams Using Integral Equations?

    I can't work out the strain energy using the integral equation here, question (b)(i). I've got the bending moment for the first beam as 400kN. E and I are given, I'm guessing you can take '2EI' out of the integral and just integrate the M^2, is that correct?
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    Conservation of Energy Question

    Having problems with part (c) here, question is attached below in full. Homework Statement Using the equation 1/2 * Load * Displacement = Sum of (P^2 * L/2AE) From the past questions I have the following info, these are also included in the solutions so are accurate: A = 1x10^3 m^2 FAB =...
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    Tensile Stress at Mid-span of Beam

    So my yc value for for compressive stress must be incorrect, yes? I still have no idea how to work out the tensile stress at mid-span.
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    Tensile Stress at Mid-span of Beam

    I am using the correct units and figures. The only figure that changes from working out the tensile stress and the compressive stress is the yc/yt value - correct? yc = 400 - 118.33 = 211.67, using those figures doesn't bring the correct answer. To clarify the max tensile stress = 4.98 MPa and...
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    Tensile Stress at Mid-span of Beam

    y = 118.33 mm, too much working for this to type out. Icc = 762.3 x 10^6 mm^44, using formula Icc = bh^3/12 + A1*h1^2 + A2*h2^2 + A3... Bending moment is 3 m * 1000kN/m = 3kN load. 3 metres + 1/2 * 3 = 4.5 metres * 3kN M = 13,500kNm Apply σ = My / I as you say. Using yt = 118.33 to work out...
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    Tensile Stress at Mid-span of Beam

    Are you referring to question (a) and (b)? Yes, I have done them and got the correct answer, I have also done (c).
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    Shear Stress in Beams - Full Working, getting wrong

    Hi, I'm doing question (c)(ii) in the image below, full working is provided below: (c)(i) is 150kPa. I = bh^3/12 - 2 * bh^3/12 (0.25 * 0.256^3)/12 - (2* (0.119 * 0.22^3)/12) = 1.3831 x 10^-4 m^4 Q = y*A = 0.119 * 0.018 * 0.250 = 5.355 x 10^-4 m^3 shear force = (150000 * 5.355 x...
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    How can incorrect torque calculations lead to contradictory solutions?

    I do have the torque for each section, yes. Still not getting the correct solution though. I'll take you through what I've done: I have JL = 7.952 x 10^-8 and JR = 2.047 x 10^-7. I have TR = shear stress * JR/ radius of right hand side = 732.6 Nm I then calculated TL = (LR*JL / LL*JR) * TR...
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    Tensile Stress at Mid-span of Beam

    Hi, I'm struggling with finding the tensile stress at the mid-span of this beam. I've done the previous questions but have no idea how to begin with this one as I've never dealt with this question before. What is the general method? Correct answer is 1.66MPa. Thanks.
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