Week 6 Challenge

1. Summarize your study for the bending moment, shear force and deflection diagrams for the elements of the model

Answer:

Bending Moment:

• It refers to the bending of member due to the applied forces.
• In the figure below we can see simply supported beams subjected to certain udl and bending moment values are shown.
• All the supports are hinged therefore reaction at ends is zero.
• Concave shape at the centre represents the bending of the beam due to load applied.

Shear Force:

• It is defined as system of two equal and opposite forces acting side by side or at close distance.
• It occurs at the supports of a beam where there will be upward force applied at ends and reaction will be developed at the bottom hence creating a system of two equal and opposite forces.
• As per the above explanation we can see that in the below figure reaction is maximum at ends and zero at centre.

Deflection Diagrams: 

• Refers to the settling or deforming of structural members such as beams and columns.
• These components move from their place to some extent due to the applied forces.
• Allowable deflection is span/250,it it exceeds then dimensions of the members should be changed.

2. Based on the analysis design the members and outline the thought process in selecting the member sizes along with the foundation design

• The analysis of the structure is done.
• Find the element or the member which is failed.
• Find the reason for the failure of the member.
• If the member fails by bending then choose the member which is able to resist the bending.
• The member which has more section modulus that member is best selected for resisting bending.
• At the same time check for the shear failure and other failures does not occur for the replaced member.
• Similarly if the member fails by shear
• Replace the member by having good shear capacity.
• This may be defined as low shear=0.6Vd
• Also check for deflection if the member does not satisfy the limiting deflection then replace the member with the suited member as per IS 800-2007 table 6.

After checking the beam member it was failing in some criterias so increasing the size of the beam rectified the failure.

Foundation design:

The foundation member design is selected in a way that it should satisfy three conditions:

They are:

One way shear

Two way shear

The depth of the member is predicted using the one of the above three internal forces which has the worst case for failure.

The bearing capacity of the member decides the size of the footing member.