I'm having trouble in my statics class with this design project. We are to design a pedestrian foot bridge/truss structure. We are given the length the bridge must span and can use any truss design we like. The truss must be able to support a load that can be placed anywhere on the bridge. I understand this concept and have calculated the forces of all members of the truss for the different load placements. My problem is, I'm not sure how to go about choosing the cross-sectional area of the truss members to minimize cost. I'm also not sure how much deformation is acceptable in a truss. We have a few different materials to choose from and I know the costs, value of E, and other properties of each material. I guess I'm just looking for some guidance as to how to choose the cross-sectional area of the members. Obviously the smallest area possible is optimal, but again, I'm not sure how much deformation is acceptable. I just keep going in circles. Any suggestions would be greatly appreciated! Thank you!
I'm having trouble in my statics class with this design project. We are to design a pedestrian foot bridge/truss structure. We are given the length the bridge must span and can use any truss design we like. The truss must be able to support a load that can be placed anywhere on the bridge. I understand this concept and have calculated the forces of all members of the truss for the different load placements. My problem is, I'm not sure how to go about choosing the cross-sectional area of the truss members to minimize cost. I'm also not sure how much deformation is acceptable in a truss. We have a few different materials to choose from and I know the costs, value of E, and other properties of each material. I guess I'm just looking for some guidance as to how to choose the cross-sectional area of the members. Obviously the smallest area possible is optimal, but again, I'm not sure how much deformation is acceptable. I just keep going in circles. Any suggestions would be greatly appreciated! Thank you!
