DEFLECTIONS (Chapter 8) WHY? FACTORS IN DESIGN Safety Esthetics Serviceability Environment Economy DETERMINACY Determinate Structures Equations of Equilibrium Indeterminate Structures Material and Shapes

Deflection Diagrams & Elastic Curve Assumption: Linear Elastic Material Response A structure subjected to a load will return to its original undeformed position after load is removed Q: What makes structures deform? A: Internal Forces Trusses Internal Axial Forces Beams and Frames Axial Forces Shear Forces Bending Moments

Deflected Shapes Depends on Support Conditions

Deflected Shapes Depends on Support Conditions

Moment Diagrams a Good Indication

Elastic Beam Theory Linear Elastic Material Behavior Small Deformations M M M

Elastic Beam Theory Can We Relate Moments to Deflections?

Double Integration Method Boundary Conditions are of the form:

Double Integration Method