Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. m.piron

    crash box of vehicle

    Thanks for your answer. So, using deformable parts, you can ensure that the behaviour will remain the same. Maybe you're right, because I'm not mother tongue english so I don't understand completely, but in this video looks like the bolts are used to absorb energy during crash...
  2. m.piron

    crash box of vehicle

    I'm studying the bumper crashbox of vehicle, especially for formula SAE (where I find lots of information), and there are various design: square box, triangle, cone, foam, honeycomb... But I see that the australian bull bar, for this purpose, are bolted to the chassis in slotted holes, so during...
  3. m.piron

    Differences between calculation and reality

    I'm sorry but you're wrong. Suppose that I'm holding the weight over the beam, the weight touch the beam without load it. In that time, there is no load over the beam: the system have only potential energy. Then, I release the weight. Part of the potential energy will be converted into elastic...
  4. m.piron

    Differences between calculation and reality

    My assumption is, in the beginning the system have a certain potential energy, when you release the load the beam deflect, and the potential energy is converted into kinetic and elastic energy. When the beam is at the maximum deflection, all the potential energy will be converted into elastic...
  5. m.piron

    Differences between calculation and reality

    Ultimate tensile strength 360MPa Yield strength 235 MPa With statical load, it's ok. But with my suppose of 2*F, not good
  6. m.piron

    Differences between calculation and reality

    The impact is minimum. If you place a load over a spring, after certain time it stops in the equilibrium position, the travel is x=F/k and the force is F=m*g (I know that "travel" is not the correct term, but I can't translate from the italian "freccia", any help?). But in the beginning, it...
  7. m.piron

    Differences between calculation and reality

    There is no cyclic loading, the beam is static. The load is simply placed over the beam, and when done you can se a little bit of rebound. That's why I choose to use 2*F
  8. m.piron

    Differences between calculation and reality

    Good morning. I have the structure in picture. The material of the beam is steel S235. The real F is 350N, but I continuosly put and remove the load, so I take into account 2*F (found by match the elastic and potential energy, 0.5*k*x^2 = m*g*x). I found a stress of 453 MPa, so this beam...
  9. m.piron

    2D convection model

    I have to calculate this type of problem: In the right a steel pipe, with internal temperature "Ti" constant. In the left, another pipe that "shots" air at certain velocity and temperature. I want to calculate the equilibrium temperature of the right pipe. Do you know if exhist some...
  10. m.piron

    chassis stiffness on motorcycle

    It's a well known engineering rule that inside a component, the change of section must be gradual, to not create a stress-concentration zone. But the same rule should be applied between components? I'm thinking about the motorcycle fork and the motorcycle chassis: when braking, the fork and the...
  11. m.piron

    Which screw drives to choose

    I'm curious, why? It's about the reliability, easy of use, dimension...? Thanks
  12. m.piron

    Which screw drives to choose

    Good tips! but, I don't know who, and with which tools, performs maintenance. Thus I need to make the dismantling operations as simple as possible. Some screws are inserted in a counterbore, then need the allen head type. For this reason, I can use everywhere Allen screws, just to don't use...
  13. m.piron

    Which screw drives to choose

    I have to choose between Hex (external) and Allen screw drives. In my opinion, these are the pros/cons: Hex, pros: - less risk of strip - possibility to use a pliers, if stripped - possibility to put more torque in it - thinner head Hex, cons: - aesthetically, not beautiful - in a...
  14. m.piron

    Which theory for an hand calculation

    then, summarizing: 1) my assumption of "neutral line" was wrong, I must consider two separate beam. 2) I must follow the loadpath from load to reactions, and look each component how it react. I try to repeat the hand calculation and the fem. I obtain results nearest to the fem if I think about...
  15. m.piron

    Which theory for an hand calculation

    The two beams are connected together by two plate 248x180x20 mm at each side, you can see it in the right drawing. All the component are welded. I consider the two beam as a single beam, and the neutral line is the line that don't change lenght with deformation of the beam... but maybe you're...
  16. m.piron

    Which theory for an hand calculation

    Good morning, I need to made an hand calculation of this component: I verified it also with FEM, but I want to find the right theory to calculate it by hand. 1)I found the neutral line. 2)I calculate the stress on the lower and upper surface with the beam theory (but the L/H ratio is very...

Part and Inventory Search

Back
Top