Recently I found a description about beam element in Abaqus manual 2018. Please check the short paragraph below.

This extension leads to Timoshenko beam theory (Timoshenko, 1956) and is generally considered useful for thicker beams, whose shear flexibility may be important. (These elements in Abaqus are formulated so that they are efficient for thin beams—where Euler-Bernoulli theory is accurate—as well as for thick beams: because of this they are the most effective beam elements in Abaqus.)

So... that means beam element in Abaqus is based on Timoshenko beam theory?