Hello Makamalla NAVEEN Kumar, the rapid decrease in load after reaching the maximum could be due to several factors: Check if the material model is correctly defined, especially if any non-linear properties are affecting the response. Ensure that the boundary conditions are applied correctly and are not allowing excessive movement or rotation. Poor mesh quality can also lead to convergence issues. Verify the mesh and refine it if necessary, and If you are using a displacement-controlled load, ensure it's applied gradually to avoid abrupt changes in load.

@Ravi P. Singh Thankyou sir

Do you have Non linear properties for comprehensive strength of 65 MPa

Based on my experience, most probably the reason is the way you apply the prestressing. Could you explain how you apply prestressing force or stress to the reinforcements of your beam?

Generally in practice, the prestressing has transition steps in boundary edges due to the release of the stress. In boundary regions, the prestressing value is less than what is supposed to be. Therefore, you should apply a stepwise prestressing to your reinforcements starting from a low value and increasing to the desired value.

Hope it helps,

Bests,

Nima Kian

I am applying the prestress as predefined load in abaqus.

Giving the predefined load in step 1 as initial.

And I modeled prestressed strand as a Truss element.

I am observing my prestress loss is 9%.