Assignment | % | DUE |
1. Form Design of a C Frame: Stress/Deflection analysis | 10% | Week 5 |
2. Simple Cantilever1: Comparing FEA against formula results | 6% | Week 7 |
3. Simple Cantilever2: Gravity, Scale, Slenderness effects. | 7% | Week 8 |
4. Universal Beam Cantilever: I, Beam Tables, Design. | 7% | Week 9 |
5. Beam Lab and quiz. | 10% | Mid Sem |
6. Design Analysis of a Clamp. | 20% | Week 13 |
7. Bolt Head Design | 20% | Week 15 |
8. Combined Project - Class or student-preferred project | 20% | Week 17 |
Total | 100% |
The profile of the part must not intrude into the 50mm
radius or the 10mm flat face. You can make it as large as you like and any shape - but we are trying to minimize weight!. The mounting must be 40mm long and horizontal, and at least 50mm from the jaws. (i.e. behind the centre of the inner hole of diam 100mm) |
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The force should be applied as a pressure load over the
area
of the flat face. We do not use a point force due to excessive stress
produced by the force concentration. Remember to refine the mesh to check your results more thoroughly. |
Width: 20-40mm Height: 30-60mm Length: 1000-2000mm |
Example Calculations: Assume a force (F) of
500N, a cantilever with
length (L) of 1.5m. The beam is 50mm wide x 100mm deep. Find the stress. Bending Moment M = F * L = 500 x 1500 = 750000 Nmm (you must use mm) Section Modulus Z = b * d^2 / 6 = 50 x 100^2 / 6 = 83.333 e3 mm^3 Note: Z is actually derived from the Second moment of Area (I) using the equation Z = I / y , where y = distance from Neutral Plane to furthest extent of the beam cross-section…often half the depth. Now, I is based on the shape of the cross-section, and for a rectangle it is I = b * d^3/12. Therefore Z = I / y where y = d/2, so… = b * d^3/12 * 2/d = b * d^2 / 6 Formula for stress: Stress s = M / Z = 750E3/83.33E3 = 9 MPA |
Cantilever. Use Solid Edge to model a standard beam
section. (200UB – 18.2 kg/m) |
Material. Grade 8.8. (For details see http://www.matweb.com, or go to the bolt grades listed in MEM)
Loading. This part must be designed to endure >106 cycles. See Fatigue
info.
Length. 400mm.
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Load
the bolt in tension. Ignore the thread of the bolt and assume a shank length of
at least 50mm - yet try to minimize mesh size.
(a) Calculate the maximum load for the 8.8
bolt. Ensure you have a fine mesh to maintain accuracy.
(b) Re-design the
bolt-head to reduce the
stress concentration at the shank/head connection. The load must
be applied on a flat circular surface under the head with inside
diameter of 19mm and outside dimaeter of 25mm diameter. Demonstrate the
effect of corner radius and shank relief groove.
(c) Calculate a 10^6 fatigue load for the
bolt. (in kg)