Shear Force
CEMB 121 MECHANICS OF MATERIALS LABORATORY
EXPERIMENT (NO.2 (a))
SHEAR FORCE I
SUMMARY Shear Forces occurs when two parallel forces act out of alignment with each other. For example, in a large boiler made from the sections of sheet metal plate riveted together, there is an equal and opposite force exerted on the rivets, owing to the expansion and contraction of the plates. The shearing force (SF) at any section of a beam represents the tendency for the portion of the beam on one side of the section to slide or shear laterally relative to the other portion.
The diagram above shows a beam carrying loads W1, W2 and W3. It is simply supported at two points where the reactions are R1 and R2. Assume that the beam is divided into two parts bya section X-X. The resultant of the loads and reaction acting on the left of A-A is vertically upwards and since the whole beam is in equilibrium, the resultant force to the right of A-A must be F downwards. F is called the Shearing Force at the section A-A. It may be defined as follows; the shearing force at any section of a beam is the algebraic sum of the lateral components of the forces acting on either side of the section. Where forces are neither in the lateral or axial direction, they must be resolved in the usual way and only the lateral components are used to calculate the shear forces. There is different types of load. A beam is normally horizontal and the loads vertical. Other cases which occur are considered to be exceptions. A concentrated load is one which can be considered to act at a point, although in practice it must be distributed over a small area. A distributed load is one which is spread in some manner over the length or a significant length of the beam. It is usually quoated at a weight per unit length of beam. It may either be uniform or vary from point to point.
STATEMENT:
This test is performed to determine that the shear force at a cut section of a beam is equal to the algebraic sum of the
EXPERIMENT (NO.2 (a))
SHEAR FORCE I
SUMMARY Shear Forces occurs when two parallel forces act out of alignment with each other. For example, in a large boiler made from the sections of sheet metal plate riveted together, there is an equal and opposite force exerted on the rivets, owing to the expansion and contraction of the plates. The shearing force (SF) at any section of a beam represents the tendency for the portion of the beam on one side of the section to slide or shear laterally relative to the other portion.
The diagram above shows a beam carrying loads W1, W2 and W3. It is simply supported at two points where the reactions are R1 and R2. Assume that the beam is divided into two parts bya section X-X. The resultant of the loads and reaction acting on the left of A-A is vertically upwards and since the whole beam is in equilibrium, the resultant force to the right of A-A must be F downwards. F is called the Shearing Force at the section A-A. It may be defined as follows; the shearing force at any section of a beam is the algebraic sum of the lateral components of the forces acting on either side of the section. Where forces are neither in the lateral or axial direction, they must be resolved in the usual way and only the lateral components are used to calculate the shear forces. There is different types of load. A beam is normally horizontal and the loads vertical. Other cases which occur are considered to be exceptions. A concentrated load is one which can be considered to act at a point, although in practice it must be distributed over a small area. A distributed load is one which is spread in some manner over the length or a significant length of the beam. It is usually quoated at a weight per unit length of beam. It may either be uniform or vary from point to point.
STATEMENT:
This test is performed to determine that the shear force at a cut section of a beam is equal to the algebraic sum of the