Types of End Supports of Frames

Types of End Supports of Frames:

Like the end supports of a beam, frames may also have the following types of supports:

1. Frames with simply supported ends:

It is a theoretical case in which the ends of a frame are simply supported. In such a case, both reactions are always vertical and may be found out by the principle of moments by equating the anti-clockwise moments and clockwise moments about one of the supports.

2. Frames with one end hinged and the other supported freely on rollers:

Sometimes, a frame is hinged at one end and freely supported on rollers at the other end. If such a frame carries vertical loads only, the problem doesn’t present any special features. Such a problem may be solved just as a simply supported frame.

But sometimes such a frame carries horizontal or inclined loads. In such a case, the support reaction at the roller-supported end will be normal to the support. The support reaction at the hinged end will be the result of:

1. Vertical reaction, which may be found by subtracting the vertical component of the support reaction at the roller-supported end from the total vertical loads.

2. Horizontal reaction, which may be found by algebraically adding all the horizontal loads.

3. Frames with both ends fixed:

Sometimes, a frame or a truss is fixed or built-in at both ends. In such a case, the reaction at both the supports can’t be determined, unless some assumption is made. The assumptions usually made are:

1. The reactions are parallel to the direction of the loads.

2. In the case of inclined loads, the horizontal trust is equally shared by the two reactions.