How Do I Draw This Shear and Moment Diagram?

[pawer]

Hi everyone,

Can anyone tell me how do I draw the shear and moment diagram of below pic



using the method like below pic?



This is my attempt/work of the reacting forces:



Thank you very much for the help.

 

[Chestermiller]

Where did that reaction force come from?

 

[pawer]

I think since it's on equilibrium state, so the reaction forces can be easily found.

 

[Lnewqban]

I think since it's on equilibrium state, so the reaction forces can be easily found.

Welcome!
But if the only point of anchorage of the beam to the ground is exerting 450 kN of vertical force to keep that equilibrium state, which vertical loads are inducing that reaction?

 

[pawer]

Welcome!
But if the only point of anchorage of the beam to the ground is exerting 450 kN of vertical force to keep that equilibrium state, which vertical loads are inducing that reaction?

It was my mistake, sorry. It should be 60 kN.

 

[Chestermiller]

It was my mistake, sorry. It should be 60 kN.

View attachment 364134

View attachment 364134

OK. Let's see your moment balances now.

 

[pawer]

How do I draw the Shear and Moment diagram of this problem?

 

[Lnewqban]

How do I draw the Shear and Moment diagram of this problem?

Have you done it before for simpler cases?

 

[Chestermiller]

OK. Let's see your moment balances now.

You write an equation for the shear stress and bending moment vs x for each section of the beam. You then plot these equations on a graph.

 

[pawer]

Have you done it before for simpler cases?

I can draw the shear and moment diagram like post #1.

The book I am reading about shear and moment diagram does not show example of what I'm asked.

At which point the x is located so that I can find the function of x of this problem?

 

[Lnewqban]

At which point the x is located so that I can find the function of x of this problem?

There is no point at which x is located.
For each cross-section of the beam represented by any x distance from the point of anchorage to the wall along the beam, there are specific values of shear and moment loads.

Without doing any calculation, we know that the beam's cross-section that is resisting the maximum value of moment is located at the point of anchorage A, and that the end of the beam (cross-section E) will not be fighting any moment.

The intensity of the resisting moment will decrease squarely from A to E, but not following a single parabola because the pattern of the load distribution changes at point C.

The shear-moment combined loads that the cross-sections located between E and C are resisting could be analyzed as if that length of the beam were anchored to a wall located at C (this would not work for calculations of the beam's deflection).

The analysis of the shear-moment combined loads that the cross-sections located between A and C are resisting would need to consider the actual shear and moment loads that the section located at C is experiencing (as previously analyzed above).

 

[robphy]

Possibly useful:
https://engineeringstatics.org/Chapter_08-geogebra-interactives.html