Maximum bending moment in aluminium alloy beam

[Solidsam]

I have three questions and need to calculate the magnitude of the maximum bending moment

1) A 4 m long aluminium alloy beam, simply supported at its ends, carries a central
concentrated load of 2 kN. The T-cross-section of the beam (see Figure A2)
consists of a rectangular flange and web with similar dimensions 75 mm by 15 mm,
giving an overall depth to the section of 90 mm, where the load rests upon the top
surface of the flange.

2) A 10 m long cantilever steel beam, carries a central concentrated load of 1 kN at its
free-end. The T-cross-section of the beam (see Figure A2) consists of a rectangular
flange and web each having similar dimensions 100 mm by 20 mm, giving an overall
depth to the section of 120 mm, where the load rests vertically upon the top surface of
the flange.


3) A steel cantilever, 8 m long, carries a central concentrated load of 2 kN at its freeend.
The T-cross-section of the beam (see Figure A2) consists of a rectangular
flange and web each having similar dimensions 75 mm by 15 mm, giving an overall
depth to the section of 90 mm. The load rests upon the top surface of the flange.





I know the formulas M=WL/4 M=wl^2/8 WL=wl^2/2


The problem is i don't know how to use the formulas

 

[PhanthomJay]

There are several cases where max moment formulas should be memorized for the respective case, but in general, they should be calculated using the equilibrium equations. For a cantilever, the max moment occurs at the fixed end, so calculate the moment produced by the concentrated load about that end. For a simply supported beam with a concentrated load, the max moment occurs at the point of application of the load. Are you also looking for max bending stress? You should first read up on how to calculate shears and moments and how to draw shear and moment diagrams and free body diagrams.

 

[Solidsam]

yeah thanks for the reply sorted it out now