Hi. 

I create a simple I-Section Beam as shown in screen captures. Both the ends of the beam are fixed (ENCASTRE) and the entire beam length (8000mm) is loaded with a UDL of 20 N/mm.

My expected Result for moments is 106 KN-m at the ends and 53 KN-m at the centre node (also shared in screen capture). But ABAQUS RESULTS show reaction moment = 0 at the centre.

Also, from the formula, section modulus Z = (BD^3 - bd^3)/6d = 329933.5 mm^3. Therefore, Stress = moment/Z = 106E06/Z = 321 MPa at the ends and 53E06/Z = 160 MPa at the centre node. But in ABAQUS, the mises stress at the ends is 241 MPa and at the centre it is giving correct value of 161 MPa.

Why is the stress value at the end node and the moment value at the centre node not matching with hand calculation?