Recent content by mattyboson12

  1. mattyboson12

    Control systems -- input with non-zero initial conditions

    1. Homework Statement Deriving an s-domain equation for the following inputs a) &b) 3. The Attempt at a Solution I understand how to derive the equation for an input with zero initial conditions (part a) but I'm not sure what to do when there are non-zero initial conditions (part b)
  2. mattyboson12

    Composite lay-up

    1. Homework Statement a)Describe a potential laminate lay-up that would exhibit high shear stiffness b)Describe a potential laminate lay-up that would exhibit a low poissons ratio 3. The Attempt at a Solution a) is a unidirectional lay-up in the direction of the shear force best? b) an evenly...
  3. mattyboson12

    Radial/Hoop stress in a steel turbine disc

    1. Homework Statement 2. Homework Equations -given in question 3. The Attempt at a Solution I am bit confused with the boundary conditions of this problem. I understand the radial stress is zero on the inside diameter and the radial stress on the outside diameter will be the reaction to...
  4. mattyboson12

    Material selection for vehicle leaf spring

    1. Homework Statement I've gone though a material selection process to pick the optimum material for a rear leaf spring suspension for a vehicle (~700mm long) and I've selected the top 10 materials based on fatigue, fracture, toughness, cost, yield etc: -Stainless steel, martensitic, AISI...
  5. mattyboson12

    Material selection based on either U1 or U2 merit index

    1. Homework Statement Choose a component based on either U1 or U2 merit index and select what you believe to be the optimum material. 2. Homework Equations U1=(σ)^2/E (Energy density) U2=(σ)^2/(Eρ) (specific energy density) 3. The Attempt at a Solution I was going to use a spring damper...
  6. mattyboson12

    Von Mises stress

    Thank you
  7. mattyboson12

    Von Mises stress

    If the von mises stress well is below the yield stress, am I right to assure the material is behaving elastically?
  8. mattyboson12

    Picking an element type for FEA

    When choosing between a 2D 4-node quadrilateral element and 8-node for FEA stress analysis, why is the 8 node option preferred? I understand it has much more flexibility with different shapes due to the central mid node but are there any other reasons?
  9. mattyboson12

    Proximity Sensor, Design Project

    I've taken a year out of university to work at a design company and they have given me a project to design/make a test rig which measures the position of a metal shaft within an actuator assembly to check if its within a +/- 0.2mm tolerance. Some of the key requirements are: No contact with...
  10. mattyboson12

    Thermal Resistance

    1. Homework Statement Explain how the concept of thermal resistance can be used in the analysis of heat transfer problems 2. The attempt at a solution So I'm made a few key points but I am not sure if I have answered the question fully: Thermal resistance is a heat property and a...
  11. mattyboson12

    Surface temperature of a tile

    I've double checked my code and all the methods seem to be okay. Yep, i have used the tri-diagonal matirx and then the built in function tdm() to solve the matrix Matt
  12. mattyboson12

    Surface temperature of a tile

    Hi Chet The program calculates the temperature using fourier's equation in one dimension: dU/dt=α*(d^2 U/d^2 x) . I'm guessing crank is the best method as it seems to have the best compromise between stability/accuracy compared to the others. I am just confused as to why the differencing...
  13. mattyboson12

    Surface temperature of a tile

    Hi, I have written a matlab program to calculate the surface temperature on a tile and I am trying to find the most stable/accurate differenceing technique. I have plotted the surface temperature (where its actual value is ~122.5) against the time step for the differencing techniques shown...
  14. mattyboson12

    Flat-pack coffee cup

    Hi, I am a 2nd year student studying Mechanical Engineering. As part of our design module we are doing a feasibility analysis into a 'disposable Fold-flat cup with an integrated lid' which is to replace existing coffee cups. I understand their are some patents for similar products which would...