What is structure analysis?:
Structure is a combination of members connected together in such a way
to serve a useful purpose.
Structure Analysis is a method by which we find out how a structure or a member of a structure behaves when subjected to different loads. The results of the analysis are used to verify the structure’s strength for its uses. Structural analysis is thus a key part of structural engineering.
Structural members subjected to a tensile force are often referred to as tie rods or bracing struts. Due to the nature of this load, these members are rather slender, and are often chosen from rods, bars, angles, or channels
Beams are usually straight horizontal members used primarily to carry vertical loads. Beams are primarily designed to resist bending moments. They are often fixed ,or pin supported and can be in the form of a steel plate girder, reinforced concrete, or laminated wood.
Members that are generally vertical and resist axial compressive loads are referred to as columns. Tubes and wide-flange cross sections are often used for metal columns, and circular and square cross sections with reinforcing rods are used for those made of concrete. Occasionally, columns are subjected to both an axial load and a bending moment as shown in the figure. These members are referred to as beam columns.
Types of structures:
When the span of a structure is required to be large and its depth is not an important criterion for design, a truss may be selected. Trusses consist of slender elements, usually arranged in triangular fashion. Due to the geometric arrangement of its members, loads that cause the entire truss to bend are converted into tensile or compressive forces in the members. Because of this, one of the primary advantages of a truss, compared to a beam, is that it uses less material to support a given load
Frames are often used in buildings and are composed of beams and columns that are either pin or fixed connected. Like trusses, frames extend in two or three dimensions. The loading on a frame causes bending of its members, and if it has rigid joint connections, this structure is generally “indeterminate” from a standpoint of analysis. The strength of such a frame is derived from the moment interactions between the beams and the columns at the rigid joints.
Types of loads:
Dead loads (DL):
Dead loads consist of the weights of the various structural members and the weights of any objects that are permanently attached to the structure. Hence, for a building, the dead loads include the weights of the columns, beams, and girders, the floor slab, roofing, walls, windows, plumbing, electrical fixtures, and other miscellaneous Attachments.
Live loads (LL):
Live loads can vary both in their magnitude and location. They may be caused by the weights of objects temporarily placed on a structure, moving vehicles, or natural forces. The minimum live loads specified in codes are determined from studying the history of their effects on existing structures. Usually, these loads include additional protection against excessive deflection or sudden overload.
Environmental loads are loads which are due directly or indirectly to environmental actions, exemples of these loads:
- Wind: is primarily horizontal load caused by the movement of air relative to earth. Wind load is required to be considered in structural design especially when the height of the building exceeds two times the dimensions transverse to the exposed wind surface.
- Snow: constitute to the vertical loads in the building. But these types of loads are considered only in the snow fall places.
- Earthquake: constitute to both vertical and horizontal forces on the building. the horizontal movement of the building at the time of earthquake is to be considered while designing.
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