Hello, guys. Welcome back. It’s been ten weeks into the coding period. I had a meeting with Jason on 25th of this month. We discussed many new changed on the API that I had implemented before this week. Now, the beam bending module is almost ready to solve beam bending problems.

Let us see how to solve a beam bending problem using this module.

Problem Statement :

The deflection is restricted at the end of the beam.

Solution :

```
>>> from sympy.physics.continuum_mechanics.beam import Beam
>>> from sympy import Symbol, Piecewise
>>> x = Symbol('x')
>>> E = Symbol('E')
>>> I = Symbol('I')
>>> b = Beam(4, E, I)
>>> b.apply_load(value=-9, start=4, order=-1)
>>> b.apply_load(value=-3, start=0, order=-1)
>>> b.apply_load(order=0, start=2, value=6)
>>> b.bc_deflection = [(4, 0)]
>>> b.boundary_conditions
{'deflection': [(4, 0)], 'moment': [], 'slope': []}
>>> b.load
-3*SingularityFunction(x, 0, -1) + 6*SingularityFunction(x, 2, 0) - 9*SingularityFunction(x, 4, -1)
>>> b.shear_force()
-3*SingularityFunction(x, 0, 0) + 6*SingularityFunction(x, 2, 1) - 9*SingularityFunction(x, 4, 0)
>>> b.bending_moment()
3*SingularityFunction(x, 0, 1) - 3*SingularityFunction(x, 2, 2) + 9*SingularityFunction(x, 4, 1)
>>> b.slope()
(3*SingularityFunction(x, 0, 2)/2 - SingularityFunction(x, 2, 3) + 9*SingularityFunction(x, 4, 2)/2 - 7)/(E*I)
>>> b.deflection()
(-7*x + SingularityFunction(x, 0, 3)/2 - SingularityFunction(x, 2, 4)/4 + 3*SingularityFunction(x, 4, 3)/2)/(E*I)
```

If the user wants to represent the deflection in the piecewise form, then:

```
>>> b.deflection().rewrite(Piecewise)
(-7*x + Piecewise((x**3, x > 0), (0, True))/2
+ 3*Piecewise(((x - 4)**3, x - 4 > 0), (0, True))/2
- Piecewise(((x - 2)**4, x - 2 > 0), (0, True))/4)/(E*I)
```

**Next week **

**Next week**

- Add the end argument in the apply_load method.
- Add Sphinx documentations.

That’s all for this week. Cheers !!

Happy Coding.

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