What part does the geometry and orientation of the members p

What part does the geometry and orientation of the member’s play in the deflection of the beam?

Solution

the deflection of beam depends on the flexural rigidity of the beam(EI)

so here E is nothing but the modulus of elasticity it depends on the type of material

I is moment of inertia it depends on the geometry and orientation of beam crossection.

for given area the best section for beam is I-section since the moment of inertia is more for I-section compare with othe shapes of crossections.

the deflection of beam is inversly proportional to the moment of inertia of section

consider rectangular section

the moment of inertia when neutral axis perpendicular to the depth = bd³/12

when neutral axis perpendicular to width then I = db³/12

so the moment of inertia is depends on the orientation of crossection and the geometry.