Recent content by peleus

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    Calculating Weld Sizes for Staircase Attachments

    Hi all, I'm trying to learn to do some basic calculations for welding, and I've been given the task in regards to finding out the weld sizes required for the loads being applied. I've got a 1.2m wide staircase, with 6 stairs, attaching to two angular beams on the outside. They will be...
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    How to Calculate Shelf Sag for an Acrylic Hot Air Dryer?

    Thanks for spotting the mistake. Stupid me. The equation is definitely right in the following sense. Stiffness = C1 * E * I / L^3 Stiffness = force / deflection. So force / deflection = C1 * E * I / L^3 Therefore, deflection = L^3 * F / C1 * E * I I changed 2.5 GPa to MPa in my outline...
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    How to Calculate Shelf Sag for an Acrylic Hot Air Dryer?

    I = 0.5m * 0.008m^3 / 12 I = 2.13333x10^-8 m^4 defl = 50 N * 0.5m / (384/5) * 2.5x10^6 Pa * 2.13333x10-8 m^4Pascals cancels a m^2 down the bottom and N up the top leaving m / m^2 This gives m^-1 which I suppose can't be right, any idea where I've gone wrong though?
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    How to Calculate Shelf Sag for an Acrylic Hot Air Dryer?

    Any chance you can help me out with finding the stress in the shelf? I'm using defl = Force * Length^3 / Second moment of Area * Creep Modulus * Loading constant. I don't think this is right, because I'm getting a deflection of 6.1m (obviously wrong) and I don't think this method takes...
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    How to Calculate Shelf Sag for an Acrylic Hot Air Dryer?

    Hi all, I'm trying to crack what is admittedly a homework question. I don't necessarily want you to just spit out the right answer for me, but if you could point me in the right direction it would be appreciated. A shelf for a hot air dryer is to be made from acrylic sheet. The shelf is...
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    How Does Tank Shape Affect Water Stream Pressure and Trajectory?

    Homework Statement Hi all, I'll outline the situation first, then I'll ask about what I need. Tank (designed by me / other students) which has no closed in top or bottom. Can be any shape, i.e. cylinder / cone / square etc etc. Made from cardboard with plastic bag in the middle acting...
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    Solving for Vertical and Horizontal Forces in a Statics Problem

    Edit - Wrong, redoing working. Ok, if someone can confirm this for me I'll be forever in your debt. Using the sine rule we find angle ACD to be 57 deg. This leaves angle CAD to be 73 deg. This also means the beam is 17 deg above the horizon. The result of this is that the weight's have 73...
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    Solving for Vertical and Horizontal Forces in a Statics Problem

    I haven't learned particular form yet. Any chance you can show me how to do it so I can learn by your working? I completely understand the idea behind hinting along so someone can work it out for themselves but I think it will just be easier if I can see someone elses working so I'll know...
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    Solving for Vertical and Horizontal Forces in a Statics Problem

    Homework Statement http://home.exetel.com.au/peleus/EIDEprob.jpg 2. The attempt at a solution Basically did the standard sum of moments around point A to try and get the vertical component of point D. -6.2*997 + 9.2*Dy - 12.4*1472 Dy = 2655.89 From there working out Dx...
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    Determining Fracture Point for Materials: Quick Guide for Engineering Students

    Hi NVN, thank's for your response. 1) The current cross sectional dimensions are 25 mm (h) x 1.5 mm (w), 2) I want to load it almost to the point of rupture, or more importaintly, know HOW to figure out the point of rupture. 3) I have no idea, I haven't got access to material to test or find...
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    Determining Fracture Point for Materials: Quick Guide for Engineering Students

    Hey all, Back looking at this problem again. I've developed it a little further, and now I have the maximum stress being 67.44 and the maximum bending moment of 2452.5. It's two parallel beams 1cm apart taking a force of 24.5N in the centre of a 400mm span. Total second moment of area is...
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    Determining Fracture Point for Materials: Quick Guide for Engineering Students

    Two weeks into uni I'm smart enough to know I know nothing :) Formula's I know are things such as Stress = Load / Area Strain = (l -l0) / l0 Deflection formula Can calculate the second moment of area of it. Can probably look up information about the material for other things...
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    Determining Fracture Point for Materials: Quick Guide for Engineering Students

    Hi all, I'm a 1st year (first 2 weeks) engineering student, with a quick question in regards to fracture points of materials. We're currently going through the elastic modulus and the deflection formula, which is pretty handy and I think I've got a decent (basic) grasp on it now...
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    Second moment of area - Need walkthrough

    Hi all, I'm at uni starting off engineering, and I'm looking for a walk through in this algebra involved in the second moment of area. While I know it's probably pretty basic I'm undertaking a bridging course to try and keep up with my maths. http://home.exetel.com.au/peleus/smoa.jpg...
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