The below figure shows a stepped bar structure that consists of three elements.

The structure is fixed in the left$-$hand side.

A $20(kN)$ load is applied at the position of $100(mm)$ from left and a $10(kN)$ load is applied

at the end right$-$hand side.

Develop a finite element model to find the below:

a$)$ Using direct stiffness method, determine the nodal displacement of stepped bar. Elastic

Modulus of the material $(E)$ is $200(GPa).$

b$)$ Determine reaction at the support and

c$)$ Determine the stresses in each element.

Please note that you must solve the problem by using the Partition Method.