Activity 2.1.1 Centroids
Hand Calculations
Complex Shape / Physical Cross Section #1 Centroid Measurements
The centroid for this physical cross section was found using the string technique. I used a plump bob, string, and a washer. The physical cross section was made of card stock graph paper. However, my calculations for the centroid in the x direction were off by 0.25 inches in comparison to the calculations in the x direction when done by hand. My calculations for the centroid in the y direction was off by 0.43 inches in comparison to the calculations in the y direction when done by hand. The centroid in the x direction is 1.5 inches from the reference side and in the y direction is 2.25 inches from the reference side.
Complex Shape / Physical Cross-Section #2 Centroid Measurements
The centroid for this physical cross section was found using the string technique. I used a thumbtack, yarn, and a roll of electrical tape. The physical cross section was made of card stock. The centroid in the x direction is 1.75 inches from the reference side and in the y direction is 2.3125 inches from the reference side.
MD Solids Calculations
When I created the shape in MDSolids 4 I couldn't use the Z-Shape format because it didn't include all the measurements I needed to accurately demonstrate the shape's dimensions.
Conclusion
Upon finishing my calculations, I discovered that in MDSolids 4 were accurate in the y direction but off by 0.25 inches in the x direction. The calculations for the first physical cross-section were off by 0.25 inches in the x direction and they were off by 0.43 inches in the y direction. The calculations for the second physical cross-section were accurate in the x direction and were off by 0.3675 inches in the y direction.