Can I know what turning "Include Shear Effects" ON or OFF does in SACS?

As the name suggests, this option includes the effects of shear deformation when calculating stiffness and deflection of beam elements. It is usually turned on when beams with a deep web or more specifically, low Length/Depth ratio are being used but it will have some effect on all beams. See en.wikipedia.org/.../Timoshenko_beam_theory

Thanks for helping me out with this.

Shear deformation effect shown in option card will be followed Timoshenko beam theory

They have 2 beam theories which is Euler-bernoulli and Timoshenko. Normally, most of people will known Euler-bernoulli (Classic Beam Theory) which assume 'section remain plane when it is bended'.

Timoshenko beam theory will count this part into bending moment calculation. You will see that we have to give 'shear stiffness properties' when we try to calculate bending moment of the beam in Timoshenko formular while it is do not needed in classic beam theory.

This shear effect will give little effect in thin and long beam while it will significant in 'thick and short beam.

Shear deformation effect shown in option card will be followed Timoshenko beam theory

They have 2 beam theories which is Euler-bernoulli and Timoshenko. Normally, most of people will known Euler-bernoulli (Classic Beam Theory) which assume 'section remain plane when it is bended'.

Timoshenko beam theory will count this part into bending moment calculation. You will see that we have to give 'shear stiffness properties' when we try to calculate bending moment of the beam in Timoshenko formular while it is do not needed in classic beam theory.

This shear effect will give little effect in thin and long beam while it will significant in 'thick and short beam.

Thanks a lot for the detailed explanation.