Ch 6. Structures Multimedia Engineering Statics 2-D Trusses: Joints 2-D Trusses: Sections 3-D Trusses Frames and Machines
 Chapter 1. Basics 2. Vectors 3. Forces 4. Moments 5. Rigid Bodies 6. Structures 7. Centroids/Inertia 8. Internal Loads 9. Friction 10. Work & Energy Appendix Basic Math Units Sections Search eBooks Dynamics Fluids Math Mechanics Statics Thermodynamics Author(s): Kurt Gramoll ©Kurt Gramoll

 STATICS - CASE STUDY Introduction Problem Animation Click to view movie (685k) Delta 2 Rocket (US) Click to view movie (798k) Mu-3SII Rocket (Japan) Click to view movie (84k) The lead engineer on the new Starfinder rocket must determine the force in each member of the inter-stage truss structure. If the load is too high, the first-stage thrust will buckle the truss members. What is known: The base ring radius is 1 m. The top ring radius is 0.75 m. The base and top ring are 1 m apart. The total thrust of the first-stage main engine is 2,400 kN (300 kN per joint).   Dimension Diagram Question Space Shuttle (US) Click to view movie (122k) What is the force in each of the truss members of the truss structure between the second- and third-stage rockets when the first-stage main engine is firing? Approach Sum all forces at a joint (method of joints).      ΣF = 0 Find the 3D unit vectors for all forces at the joint. Find the unknown magnitudes of the member forces.