Boundary Conditions for plane stress

I do not fully understand how to implement boundary conditions to solve my PDE (Plane stress).

Can somebody explain me how I can use BC properly?

Problem: clamped beam (boundary condition: Dirichlet) with outward load of 100 N/m. The rest of beam has Neumann as boundary condition. What do coefficients means in both conditions?

Answer 1

[Ravi Kumar]

Refer to the plate with a hole example, which shown how to apply structural loads without referring to coefficients.