ENGR 34 Chapter 6, Day 3 3D Trusses & Frames ENGR 34 Statics Chapter 6, Day 3 3D Trusses & Frames ENGR 34 Chapter 6, Day 3 3D Trusses & Frames 3D trusses Constraints & rigidity More 3D RB equilibrium practice

ENGR 34 Statics Chapter 6, Day 3 3D Trusses & Frames 3D Truss Analysis All connections assumed ball and socket All forces at joints Each joint is 3D point FBD 2 J = M + R ????? Tetrahedrons are strongest

ENGR 34 Statics Chapter 6, Day 3 3D Trusses & Frames 3D Truss Analysis All connections assumed ball and socket All forces at joints Each joint is 3D point FBD 3 J = M + R Tetrahedrons are strongest

ENGR 34 Statics Chapter 6, Day 3 3D Trusses & Frames Non Rigid Trusses Extra reactions may help

ENGR 34 Statics Chapter 6, Day 3 3D Trusses & Frames Not all parts are 2 force bodies Draw FBD’s for 3+ force bodies Use Newton’s 3rd Law

ENGR 34 Statics Chapter 6, Day 3 3D Trusses & Frames 3D Truss Key Concepts 3 J = M +R Joint method preferred Assume Tension Frames Key Concepts Use 2 force body info 3+ force body FBD’s Newton’s 3rd Law