Bending: Second Moment of Area and Solid Edge

MEM23061A rill Mechanical Engineering Materials Lab. BEAM BENDING The bending of beams is one of the virtu every last(predicate)y important types of stress in engineering. Bendingis more likely to be a critical stress thanother types of stress like tension, coalition etc. In this laboratory, we will be determining the Modulus of Elasticity E (also called Youngs Modulus) of the various materials and using Solid inch to determine the randomness sec of Area for the different cross-sections. pic Equations aim units Force (N), Length (mm), Stress (MPa) E = Youngs Modulus or Mod of Elasticity (MPa)I = 2nd fleck of Area or Area Moment (mm4). Can channelise using SolidEdge sketch. BENDING pic In our case, we must first convert the mass to Newtons (N). W = kg * 9. 81 L is the span length in (mm). I is the Second Moment of Area in (mm4). We can calculate this for a rectangle using a simple formula pic For other shapes it is not so simple. We need to calculate these using a program su ch as Solid Edge (see below). find out the value of E in MPa. From the above equation, Deflection z = W * L3 / (48 * E * I) so E = W * L3 / (48 * z * I) Determining Stress in MPa.From the above equation, Bending Moment (Nmm) M = W*L / 4 and MaximumStress (MPa) f = M * y / I where y = distance from centroid to the bottom (or fade) of the beam. This is simply half the deepness for all the symmetrical beams except the channel. To find the centroid for the channel you need to use of goods and services Solid Edge again (same as the Ixx window) pic Laboratory 1. Load another(prenominal) beam onto the rig. 2. Adjust dial estimate to ensure it is touching the beam. energy the dial face by rotating the lense and locking in place. 3. consecrate all(prenominal) load and record the deflection measurement. . Check you have all recordings Beam material, beam cross-sectional dimensions, span length, deflection readings, masses. 5. build up estimates of the errors associated with each m easurement. E. g. Parallax error, mis-alignment, mechanical play,incorrect deflections etc 5. Repeat for next beam pic Report 1. Use Solid Edge to calculate Ixx for each beam. Also determine the incubus on CAD. Draw up the cross-section (either in part way or as a draft). While you are still in the profile sketch (i. e. before going to a solid) go to top menuInspect Area gt Click Area Information passing in Ribbonbar (click inside the area you want to inspect) Click on the blue jet arrow in Ribbonbar. You should see a table like this pic Ixx is the Second Moment of Area in bending witha vertical load. 2. pull through a short report on the beam bending results. for each one beam must have at least 3 weights. Make sure the deflection does not exceed the travel of the dial index finger (if so, use a lighter weight). 3. Using the equations above, calculate the value of E. analyse these values to the values obtained fromthe internet.E. g. Matweb. Show the working for 1 exampl e calculation, but only give the rest of the answers in a table. Use stand out to do your calculations. 4. Determine the maximum stress for each mass (load) added to the beams. 5. question any sources of error in the experiment esp measurements and how they might move the results. Specify an overall error for your calculation of E. pic pic Using the dial gauge to measure deflection in the beam while under a load of 500g. pic pic The face of the dial gauge can be revolved to zero the scale.