Analysis Of Beam-Column Connections

Steel frame structures are made as the name suggest from steel, the material is strong and flexible. When weight is added it bends without cracking. Another characteristic of steel is that its plasticity or ductility, meaning that when force is added it won’t crack however it will lose shape therefore giving warning for people to evacuate the building. A disadvantage of steel is that is loses strength when subject to fire. Studies have shown that it can loose up- to half its strength when subject to fire, therefore making it imperative to cover the steel with boards or spray on.

Before the Twin Towers were built, buildings were never built to the 110 floors planned for the towers for a number of reasons. The winds in New York City could reach 100 miles per hour on some days, which caused a great amount of stress on the taller buildings in the city. Originally, buildings of the time were built with support columns ever 30 feet or so which created a solid structure but not much wide open floor space. Due to the planned height of the Twin Towers, weather could be different at the top and the bottom of the towers. To combat this, the buildings were constructed like a tube, with high-strength steel around the edges and a “core” in the middle of the buildings which was to house the elevator shafts which would help to withstand the strength of the wind and also cut down on the materials needed and therefore the cost. This was accomplished with sets of three 30-foot column lattices that were welded together offsite and then constructed at the towers using Kangaroo Cranes,

The improvement of the skyscraper structures starts from 10 floor stories to high as 150 floor stories high. The Reliance Building Chicago, USA, in 1895, 15 stories high used the semi-rigid steel frame. The semi-rigid steel frame was held together with steel beams and connected by rivets. (Bennett, P.42) The 60 stories high First Wisconsin Center, Milwaukee, USA in 1974 employed the steel belt truss with framed shear truss. This structure used the horizontal trusses at the upper and lower stories to enhance the framed shear truss. (Bennett, P.44) The Sears Tower, Chicago, USA, in 1974, 110 stories high used the Bundled tube. The bundled tubes were made up of a cluster of connected frame tubes, reinforced by steel beams at each story to increase the strength of the structure. Various tubes terminated at different level to further strengthen the bundled tubes at the center. (Bennett, P.44) The future structure was the Superframe, which can reaches at least 150 stories high. It used the concept of the Eiffel Tower with framed tubes connected by horizontal trusses. (Bennett, P.45) It was the innovation of the structural design that enables skyscrapers to reach new height. These methods include the use of

Today, some building codes may require a more rigorous structural design methodology than is associated with conventional construction. This requirement may result from a need for better building performance when the structure is exposed to moderate-to-high wind, seismic, and snow loads. An example of published

In the quake zone the Forbidden city in Beijing has stood for centuries past and in the documentary, Secrets of Chinas Forbidden City, the secret to the structural survival where unveiled. To determine the quake level that the Forbidden city building structure can withstand, a 1/5 scale model was constructed from the timber frame that is used in the palace of longevity and health. The construction method that was used is that of the traditional carpentry tools and techniques. Due to the simple joint connection that allow mobility during the earthquakes the forbidden city has lasted for centuries. The columns that holds the weight of the building are not connected to the stone bases, which allow the building to move freely and enabling the flexibility

One thing that has been brought up as a concern for the hospital is using unistrut versus structural steel to hold booms from the ceiling. Unistrut tends to move too much and causes too much movement in the booms when doctors are in surgery. The engineer on the project has started to investigate this problem and has agreed to use structural steel instead of unistrut. In my Structural Systems I class, we learned how structural steel deflects with certain

There is always a great uncertainties in predicting the loads a bridge might experience at some time in the future. One can never be certain of the weight of the heaviest truck that will cross a bridge. For that reason, my design of a truss bridge will hold a 20-ton load limit. When analyzing both the internal forces and external forces on the bridge, assumptions are made. When taking calculations the system must be modeled as in static equilibrium so we must assume that gravity is downward and that the only force is the load on the bridge .

We can see that loads are transferred from the trusses to the columns then into the foundation of the building. Engineers always assume that the loads are uniformly distributed through any building they design. I was impressed that the roof trusses are well design in the building, which shows a significant engineering work. The exposed features of roof trusses give its own uniquely design and show the glory of such engineering work.

This report aims to describe the experiment performed to investigate the stiffness of a channel section, and in particular calculate the flexural rigidity (EI) of the beam by two different sets of calculations based on the results gained in the experiment. The EI of an object is used

The infill brick walls of Specimen 5 were produced by the small windows opening. These window openings were shifted to the side of the one column at stories. Until the end of the experiment, 9 hysteresis cycles were applied to Specimen 5 at both forward and backward. Specimen 5 reached 9.14 kN lateral force and +7.56 mm displacement at 4 hysteresis forward cycle and -19.31 kN lateral force and -21.51 mm displacement at 8 hysteresis backward cycle. When Specimen 5 reached to ultimate lateral load-carrying capacity, interstory drift value was 0.7% at forward and interstory drift value was 3% at backward. Load controlled program and base shear versus second story displacement hysteresis curve of Specimen 5 are shown in Fig. 14.

There are only a very few limitations in the use of plate girders. Compared with trusses they are heavier, more difficult to transport and have larger wind resistance. The provision of openings for services is also more difficult. The low torsional stiffness of plate girders makes them difficult to use in bridges having small plan radius. Plate girders can sometimes pose problems during erection because of concern for the stability of compression

Although these problems were corrected and the idea of building a skyscraper became a feasible task, there were many conditions that had to be taken into account, that did not need consideration when building a structure less than 40 stories tall. Four story buildings are supported by their own walls; however a new method needed to be created for skyscrapers since the previous building method would not provide enough support. Metal skeletal frames made of columns and beams were then developed to provide the support and strength needed for the skyscrapers. As the buildings grew taller, their structural design was made lighter and stiffer. Also, as the buildings grew taller, wind became an important issue. Normally, the force that acts on the skyscraper pushes directly downward towards the ground that would then counter balance that push. However, when an additional force acts on it, such as wind, the forces would act differently on the skyscraper. With a lateral force acting on the building, the steel columns of the frame on the windy side would stretch apart slightly while the columns on the other side would compress. Therefore, the skeletal frame built had to be made so that the structure would be free to move slightly with the wind and, at the same time, remain sturdy.

These materials can be designed and used in the form of laminates, rods, dry fibers (sheets) adhesively bonded to the concrete, wet lay-up sheets mounted on the surface, or near surface mounted bars or laminate strips in the concrete cover [1]. Over years, a large numbers of studies on the behavior of CFRPstrengthened beams have been conducted to have a better understanding for their behavior under different loading conditions along with to develop the best technique of applying the CFRP fabric sheets and/or strips. Many drawbacks associated with the application of the CFRPs attributed to the characteristics of currently available commercial CFRP strengthening systems.

Superstructure bears the load that is being passed over the bridge and it transmits the forces caused by the same to substructure. Load received from the decking is transferred on to the substructure by Bearings. They also distribute the load evenly over the substructure material as it may not have sufficient strength to bear the superstructure load directly. Piers and Abutments are the vertical substructures which transfer the load to the earth in the foundation. Wing walls and returns are constructed as the extension of

Two papers to study the behavior of partially prestressed continuous composite beams consisting of a concrete slab supported by a steel beam were presented by Basu et al. (1987) [7, 8]. In these researches, the prestress was introduced in the negative moment regions only . The first paper presented analytical study on the effect of prestressed on crack prevention in the negative moment region and savings in material due to superior structural action. It was concluded that partial prestressing increased the load capacity of the beam by about 20% and eliminated the problem of concrete deck cracking in the negative moment region. It was also concluded that the deflection of the prestressed beam is about thirty percent less than that of the non-prestressed beam. The results of tests on a model of continuous