服装导购必须知道的销售技巧（四）.ppt

DESIGN AND DEVELOPMENT OF AN ECONOMICAL TORSION TESTING MACHINE by Glenn Vallee, Ph.D., P.E. And Robert Short Mechanical Engineering Department Western New England College Project Objectives Design and build a torsion testing machine capable of performing the ASTM Torsion Test Machine must measure material properties to within 5% of published data Machine must be affordable Torsion Testing Apparatus Experimentally determines torsional shear properties of materials A cylindrical test specimen is twisted until failure Applied torque and angle of twist are recorded ASTM Standardized Test Method Used- Specifies Test Procedure / Specimen Geometry Design Constraints Machine must be capable of fracturing a steel test specimen Specimen diameter to be 3/8 inch to allow examination of fracture surfaces- ASTM therefore requires a specimen length of  6 inches to meet the min length/diameter ratio Torque and angle of twist measuring devices to be easily accessible to students Design Constraints Machine must produce measurements within 5% of published ASTM results Budget allocation of $500 Many Years of Service!!! Determination of Shear Properties Determination of Shear Properties Shear Modulus G is determined by finding the slope of the shear tress-strain diagram Shear modulus may also be calculated using Design – Torque and Angle of Twist Requirements Equation (1) was used to estimate the torque required to yield a C1018 plane carbon steel test specimen in torsion 3000 in-lb would be required to fail C1018 material at constant rotational velocity Experiments were performed using aluminum to find required angle of twist (10 revolutions) Design Layout Drive Train Frame Design Measurement of Torque Measurement of Angle of Twist Chuck Alignment Torque Calibration Torque Calibration Curve Complete Assembly Performance Data Collection with Lab VIEW Testing of 1018 Cold Drawn Steel Shear modulus measured as 10.7 Mpsi, 3% lower than the published value Testing of 2014 A