1 / 6

Design Goals

This design aims to minimize material cost while ensuring sufficient Young's modulus and high fatigue resistance. The two-part mold allows for easy and cost-effective production. The design focuses on the deformation failure mode, allowing time for replacement and enhancing safety.

miyoko
Download Presentation

Design Goals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Design Goals • Function • Required Material Parameters • Sufficient Young’s modulus • High fatigue resistance • Ease with installation • Safety • Failure mode involves deformation and not fracture • Allows time for replacement • Cost • Minimize material cost • By using a reasonably inexpensive and widely used material • By minimizing volume of material used in each component • Simple two-part mold for production

  2. Two Cases for Design • Two cases where force P causes deflection of the active hook • Case 1 – end of hook where deflection is going to be just enough for it to slide past the passive hook • Case 2 – person exerts force in the middle region to unhook the latch • Case 2 will be where greater force than is needed will often be exerted • Design of lock should be based on the force P in Case 2 • Beam theory used for design

  3. Inputs Force - P Distance on beam person exerts force - a Distance in deflection - delta Width of active hook - b Modulus of material - E Length of beam - L Outputs bh3 lumped parameter - K Height of active hook - h Stress from bending - sigma Equation delta = (Pa2)(3L-a)/(6EI) where I = bh3/12 sigma = My / I where M = Pa y = h /2 and I = bh3/12 Rearranging to get K K = 2Pa2(3L-a)/(E*delta) Allows you to play with the dimensions b and h Equations for Design

  4. Active and Passive Hook Design • Optimal inputs P = 15.5 N (a little over 3 lbs.) a = 0.04 m L = 0.06 m E = 2.10E09 Pa (for ABS) delta = 0.008 m b = 0.02 m • Outputs K = 4.13E-10 m4 h = 0.00274 m sigma = 24.7 MPa Good because yield stress for ABS = 41 MPa Good safety factor!

  5. Mold Design for Active Hook

  6. Mold Design for Passive Hook

More Related