Engineering Analysis October 23, 2006 Team Moondogs Chris Culver Rahul Kirtikar Elias Krauklis Christopher Sampson Michael Widerquist

Engineering Analysis

Strength of Material Analysis for Critical Components Critical Components Critical Components Hydraulic Lines Hydraulic Lines Inner Container Inner Container Telescoping Arm Telescoping Arm Compacting Plate Compacting Plate Spring Spring Compacting Rod Compacting Rod Hinge Hinge Latch Latch

Materials Molded Polypropylene Molded Polypropylene Yield Strength = 1740 – 6240 psi Yield Strength = 1740 – 6240 psi Flexural Modulus = ksi Flexural Modulus = ksi Tensile Modulus = 72.5 – 1100 ksi Tensile Modulus = 72.5 – 1100 ksi Type 304 Stainless Steel Type 304 Stainless Steel Modulus of Elasticity = 28,000 ksi Modulus of Elasticity = 28,000 ksi Poisson’s Ratio = 0.29 Poisson’s Ratio = 0.29 Yield Strength = 31.2 ksi Yield Strength = 31.2 ksi Thus Von mises distortion energy theory will be used Thus Von mises distortion energy theory will be used

Hydraulic Inputs Ratio of input to output  Mechanical advantage Ratio of input to output  Mechanical advantage Give up output movement for force Give up output movement for force

Hydraulic Lines

Hydraulic Material Selection Decision: Use Stainless Steel Type 304 custom built tubing Decision: Use Stainless Steel Type 304 custom built tubing On all three lines the yield strength is above the von Mises failure criteria even with 2.0 SF On all three lines the yield strength is above the von Mises failure criteria even with 2.0 SF

Inner Container/Outer Container Determined through conceptual inspection that there would be minimal force exerted on the container walls Determined through conceptual inspection that there would be minimal force exerted on the container walls Since trash is mainly a solid it would not recoil against the compressing plate Since trash is mainly a solid it would not recoil against the compressing plate Due to the this a lightweight plastic, polypropylene was chosen Due to the this a lightweight plastic, polypropylene was chosen

Compacting Plate Analysis Pressure as well as force varies throughout Pressure as well as force varies throughout Force from Telescoping Rod = lbf Force from Telescoping Rod = lbf Reaction Force from Compacting Plate = 572 lbf, Pressure = 2.86 psi Reaction Force from Compacting Plate = 572 lbf, Pressure = 2.86 psi Since the Compacting Plate is connected to the Connecting Rod as well as the Lid, force there remains 572 lbf Since the Compacting Plate is connected to the Connecting Rod as well as the Lid, force there remains 572 lbf Due to lack of pressure on compacting plate polypropylene was chosen Due to lack of pressure on compacting plate polypropylene was chosen TRASH Telescoping Rod Inner Container Compacting Plate Compacting Rod

Spring Analysis Force necessary to lift 2.5 lb foot pedal Force necessary to lift 2.5 lb foot pedal Spring Coefficient k equals 0.52 lbf/in Spring Coefficient k equals 0.52 lbf/in 25/32" long brass, compression spring with closed ends 25/32" long brass, compression spring with closed ends k = 7.3 lbs/in k = 7.3 lbs/in

Compacting Rod/Telescoping Arm Buckling of Compacting Rod as well as Telescoping Arm Buckling of Compacting Rod as well as Telescoping Arm Using Type 304 Stainless Steel with Sy=31.2 ksi with max pressure at 182 psi on Compacting Rod and 2 ksi on Telescoping Arm Using Type 304 Stainless Steel with Sy=31.2 ksi with max pressure at 182 psi on Compacting Rod and 2 ksi on Telescoping Arm Deflection on Compacting Rod and Telescoping Arm Deflection on Compacting Rod and Telescoping Arm Deflection is neglible in both cases (>0.001 in) Deflection is neglible in both cases (>0.001 in)

Lid Deflection Maximum bending Stress: 10,000 psi Maximum bending Stress: 10,000 psi Only plastic supporting 572 lbf, 87 inch deflection Only plastic supporting 572 lbf, 87 inch deflection Add a 14”x14”, 1/8 ” thick steel plate to distribute the load Add a 14”x14”, 1/8 ” thick steel plate to distribute the load Max deflection of steel plate: ½ “ Max deflection of steel plate: ½ “ Plastic deflection negligible now Plastic deflection negligible now

Latch 6082A13 from McMaster-Carr Rated failure at 363 lbf, well within safety factor limit. Rated failure at 363 lbf, well within safety factor limit. Easy and simple use of operation Easy and simple use of operation Low cost < $5 (McMaster) Low cost < $5 (McMaster)

Hinge 1582A73 from McMaster-Carr 12 inch piano hinge used to distribute stress over greater length 12 inch piano hinge used to distribute stress over greater length Hinge Failure pressure at 31.2 ksi Hinge Failure pressure at 31.2 ksi Analysis yielded max stress of ksi, well within limit. Analysis yielded max stress of ksi, well within limit. Piano Hinge, Semi-Low Cost < $12 (McMaster) Piano Hinge, Semi-Low Cost < $12 (McMaster)

Fastening of Hinge/Latch Analysis of stress from bolt and plastic outer container interface yields force between 191 lbs and 686 lbs. Analysis of stress from bolt and plastic outer container interface yields force between 191 lbs and 686 lbs. The applied force for the latch and the hinge independently will be 286 lbs (split of reaction force from compacting rod) which is within the range of the hinge/latch bolts. The applied force for the latch and the hinge independently will be 286 lbs (split of reaction force from compacting rod) which is within the range of the hinge/latch bolts. Consider making plastic thicker, possibly ¼” Consider making plastic thicker, possibly ¼”

Fatigue Failure Fatigue failure analyzed for Hydraulic System and Telescoping Arm Fatigue failure analyzed for Hydraulic System and Telescoping Arm Alternating stress calculated based on cyclical full load and zero load alternations. Alternating stress calculated based on cyclical full load and zero load alternations % reliability factor % reliability factor Slave cylinder found to be weakest component, calculated to withstand 3.9E6 cycles before failure Slave cylinder found to be weakest component, calculated to withstand 3.9E6 cycles before failure Result: Fatigue not considered an issue. Result: Fatigue not considered an issue.

Weight Distribution Densities 4140 Carbon Steel = lbm/in^3 304 Stainless Steel = lbm/in^3 Polypropylene Molded = lbm/in^3 Brake Fluid = lbm/in^3

Safety and Stability Safety Issues Safety Issues Possible Stability when operating Possible Stability when operating Stability issue is solved through handles on side of trash can for better control during operation Stability issue is solved through handles on side of trash can for better control during operation

Performance Analysis and Prediction Weight = 44 lbs, within tolerable range Weight = 44 lbs, within tolerable range All components are well within stress and fatigue levels with a 2.0 SF All components are well within stress and fatigue levels with a 2.0 SF Initial Cost of components could be an issue, however mass produced cost would be reduced significantly Initial Cost of components could be an issue, however mass produced cost would be reduced significantly For design it is a feasible product For design it is a feasible product