Buckling In Steel Member Engineering Assignment Paper (Essay Sample)

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Buckling in Steel Member
Abstract
This paper discusses the behavior of steel when exposed to different types of loads in a structural member. That is when in application or use with precast concrete in the formation of engineering structures. There is a clear introduction and explanation of the particular members that experience bending moments and shear forces in a structure. Buckling has been discussed in details giving the causes and effects of buckling. In addition to that, different types of buckling have been tackled together with their respective calculations. Finally the safety factor of bucking has been considered and also calculation of critical buckling force.
The objective of this research is to identify and understand the nature of steel under different conditions. This is meant to ensure proper selection of the size of beams and columns to be used. There have been greater risks and accidents happening in many parts of the world due to the failure of buildings and other engineering structures. The accidents and failure is due to the fact that many people do not really put into consideration the effects and behavior of steel. To have the best combination of frames in storey buildings, appropriate calculations have to be carried out to facilitate proper bracing of members. This research can be a challenge to the engineering personnel who do not yet have a clear understanding of the nature of buckling of steel.
Introduction
Every structural member has to incur force depending on where it is located. A structural member may have the ability to withstand force due to its strength but at some point, it becomes challenging due to imposition of extra force. The structural member may either buckle or lose its structural form. This is majorly experienced in beams and columns. Columns are the supporting components of floors but they don’t experience the axial compression alone. Beams are also exposed to axial compression. The stress may not be preferable compression but also extensional stress. This stress depends on the constant K of the component force applied. The force may either be greater or less than the amount that the structure can support but now the type of force depends on the direction of the force. It can either be moving towards the centroid point of the structure or away from it.
Columns form part of the frame of a structure and are therefore subjected to both axial force and bending moment. The bending moment depends on the position and distribution of loads on the frame. If columns are introduced in a structural frame, it is classified as either unbraced or braced. Introduction of braces is made to ensure that the frame does not undergo stress or buckling. The braces are also made to overcome lateral loads at floor levels. If braces are not available, resistance of lateral loads is calculated in the members of the frame putting into consideration the distance of connection joints. Load is distributed evenly to avoid the structure from undergoing cracking and failing. To calculate the structural strength and durability of a member, for instance a beam, there is a need to determine whether it lies in group one components or group two components. This is essential to highlight the most appropriate resistance constant to be used.
The idea of braces is connected to buckling. They share almost the same elastic limits depending on the nature of the joints applied and even distribution of loads. Columns experience moments due to several reasons in consideration of axial compression. One of the instances is whereby the compressive nature of the load is transferred eccentrically to the column joints. When the force is transferred to the centre of the column, definitely an equal force is generated leading to bending moment and compression to the column. Another scenario is whereby the braced rigid portal joints are acted upon by gravity loads. This leads to rotation of the joints on the braced junctions hence transmission of axial loads and bending moments to the entire structure.
The applications of bending moments may also occur as a result of lateral loads caused by earthquake and wind loads. The subjection to bending and swaying later leads to axial compression in the members. When the force is subjected to maximum point, there may be formation of cracks and weak point on the structure leading to failure. Therefore the positioning of beams and column must be done in consideration of earthquake and wind loads. In this case, the correct type of beams must be used depending on the column length and width and also the load it is carrying. This is done to ensure maximum reinforcement in storey buildings. Another common aspect of bending moments is due to the formation of orthogonal directions in the entire reinforcement of columns. Due to this, the arrangement and alignment of steel members in a structure must be done to ensure maximum support and to overcome buckling.
Buckling
Buckling is a term used interchangeably mainly to refer to the failure of something. In engineering, buckling refers to the change in the structure of a structural member whereby a small adjustment - an increase in force can lead to catastrophic failure of the member. For instance, steel members, may not withstand a certain load. Therefore, addition of the load leads to sudden failure of the steel column. Frames made of steel experience buckling when the load applied overcomes and out do the elastic limit of the steel used. Thereby, steel has to be reinforced with other materials like concrete to improve its structural strength.
As used in engineering, buckling is as a result of bifurcation problem. When a certain load level is attained, there are different solutions to tackle buckling but the change in equilibrium seeks more attention. More reinforcement and distribution of loads has to be ensured failure to which buckling occurs. The load carrying capacity may increase and therefore the solution is referred to as stable in nature. Unstable and neutral paths are very dangerous since they are underestimated most of the times. Subjection of compressive force to a stress structure may lead to buckling which is as a result of sideways deflective of a structural member. At some point, it may be considered that stress is the main cause of failure but then buckling contributes to 75% of the total destruction.
A member is said to be unstable when it is unable to withstand the applied load. To respond to the changes applied, it has to undergo buckling. After buckling, there may be deformations or not. If the member is not completely deformed, the member continues to support the same load that could lead to its buckling. At this particular point, equilibrium is achieved and the distributional forces are constant. Any load applied to the structural member will be distributed evenly along the radius and length of the member and no more failure occurs. In mathematical consideration and analysis, buckling is a form of bifurcation whereby its solution solves the static equilibrium equations. The forces and moments at the end of the structure have to be considered putting into consideration the equilibrium constant. If more load is applied, the equations of static equilibrium remains constant since no more deformation is experienced. There are different types of buckling as discussed below;
Euler buckling
The behavior of structural materials was investigated by Leonhard Euler who was a mathematician in 1757 and therefore, was given the name Euler formula. He was a great philosopher who specialized in construction and furthermore he was the professor of building affairs in the United States. The idea of developing the Euler formula was a great invention to aid in the calculation of vital mathematical calculations concerning bending moments and axial forces. His main aim was to ensure that the formulas used to calculate axial forces and bending moments were simpler as compared to the past. The formula gives a simplified structure on the interdependence of different variables as applied in buckling. This was meant to ensure that buckling did not occur in structures like buildings.
The formula is designed to give maximum axial load- that is, a long slender column can hold and support without buckling. The application of this formula gives a well-structured and ideal building that can never develop weaknesses even in case of earthquakes and land movements. The column must have some properties in order to adhere to the buckling resistance properties. It should be ideal with perfectly straight edges and must be made of homogenous material and its initial states should be free from stress to avoid compromising the initial state of the formula. As soon as the applied load attains or reaches the Euler load also referred to as critical load, the column maintains the state of unstable equilibrium to counter attack the extra load. If no more loads are applied, the column or the structure remains stable but buckles when an additional load is introduced. The formula derived by Euler to deduce critical mathematical expressions is given below;
F=π2EI÷ (LK) 2
The Euler critical load formula given above has its interpretation for a better understanding. The variables are used interchangeably with the given conditions to get the intended solution. F-this denotes the vertical load applied on the column or steel structure. E -is the modulus of elasticity but keeps varying depending on the state of the material. I - denotes the area moment of inertia of the entire cross section of the structure and L is the extended and unsupported length of the column. K is the constant factor or may be considered as the length factor of the column. The end values depend on the supports available. If both ends are hinged or free to rotate, K=1.0 but if both ends are fixed, K...