# How to assign a concentrated load to a specific point in the boundary?

**URL:** <https://discourse.julialang.org/t/how-to-assign-a-concentrated-load-to-a-specific-point-in-the-boundary/82037>\
**Category:** New to Julia\
**Tags:** question, array, linearalgebra, fem, vector\
**Created:** [June 1, 2022, 8:27am UTC](https://discourse.julialang.org/t/how-to-assign-a-concentrated-load-to-a-specific-point-in-the-boundary/82037 "2022-06-01T08:27:27Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![refauhx](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@refauhx](https://discourse.julialang.org/u/refauhx)\
**Post date:** [June 1, 2022, 8:27am UTC](https://discourse.julialang.org/t/how-to-assign-a-concentrated-load-to-a-specific-point-in-the-boundary/82037/1 "2022-06-01T08:27:27Z")

</div>

Hi everyone,  
I am a beginner in Julia and I want to assign a concentrated load pointed downwards into the middle point of the boundary of my model. Unfortunately, this code gives me some results just when my tag used is a line (1D), not a point such as in this case. The code works but the stress values are 0.

I really appreciate any help you can provide.

```julia
Γ1 = BoundaryTriangulation(model, tags="upper middle point")
dΓ1 = Measure(Γ1,degree)
t1(y) = VectorValue(0.0,-100.0)
l(v) = ∫( t1 ⊙ v)*dΓ1 
op = AffineFEOperator(a,l,U,V)
uh = solve(op)    
sigma_num = evaluate(σ∘ε(uh), Point(3.0, -5.0))
show(sigma_num)

```