Steel is an alloy of carbon and iron
Steel is an alloy of carbon and iron with the carbon component forming 2% (as cast iron) (). Steel is one of the widely used building materials in the sector of construction and infrastructure. Steel has a variety of uses ranging from fabrication of small pins to large oil tankers. Moreover, most manufacturing and building tools are also made of steel. The world’s raw steel production in 2013 was approximately 1.6 billion tons (Oda et al., 2013). Steel is popular mainly because it is cheap to make, form, and process; besides, it is found in abundance as scrap and iron ore. Lastly, steel has unmatched mechanical properties, namely its great durability and formability, good thermal conductivity, good yield and tensile strength and its resistance to corrosion that makes its popularly used.
A tee-beam or simply T-beam refers to a load-bearing metal, wood, or reinforced concrete with T-shaped cross-section that is used in construction. The T-shaped top cross-section function as a compression member or a flange that resist compressive stresses. Similarly, the vertical section of the T-beam (the web) found beneath the compression flange function as a shear stress resistance by providing a greater couple force separation of bending (Ching, 1995). T-beam has many shortcomings compared to other type of beams, such as I-beam, because it does not have a bottom flange that can arrest tensile forces. However, T-beam can be more structurally efficient if it is used as an inverted T-beam with a bridge deck or floor slab joining the beams tops. When this kind of structure is undertaken correctly then the slab is used as the compression flange.
Fig. 1: Showing Webs/Vertical and Flanges/Horizontal (Shreedhar & Mamadapur, 2012)
T-beam is a simple design that contain manifold interests of design elements. The manufacturing process of steel T-beams involves four phases, which include hot rolling, extrusion, plate welding and pressure fitting. Steel T-beam has been used in many sectors including most bridges and roadways today; this is because T-beam can formed into a more practical wood, steel, concrete and composite designs. Thus, both concrete and steel can prove a better ideal in construction.
Concrete is characteristically known to be brittle hence excessive subjection to shear stresses faced by T-beam at the flange and web joint can overwhelm it. T-beam can be used together with steel to overcome shear stresses to avoid flanges failure or detachment from webs when subjected to excessive load (Paramasivam et al., 2017). A failure or detachment of flanges can be catastrophic if it occurs; hence, the need to mitigate the possibility by reinforcing the concrete using T-beams. Most beams have failed to overcome shear stresses; however, those made of composite reinforcement have demonstrated excellent bond capability due to increased ultimate strength.
2.0 Objective
This lab report aims to determine the properties of T-shaped steel beam and prepare both equal and unequal T-shaped steel beam.
3.0 Model
The report used AutoCAD software to draw and generate a 3-D Model of both equal and unequal T-beam. Figures 2 and 3 below illustrate actual pieces of T-beams for both equal and unequal structural steel. In Figure 4, Below is the AutoCAD drawings of both equal and unequal T-shaped beam structures
Actual Pieces
3D Model:
Fig. 4: 3-D model of both equal and unequal T-beams
4.0 Properties
Using MD Solid software, the T-beam properties for both equal and unequal beams were determined and captioned shown in Figure 5
Fig. 5: Demonstrating properties of T-beams displayed on a MD Solid Window (MDSolids: Educational Software for Mechanics of Materials 2020)
Fig. 6: Displaying a screenshot of T-beams properties analyzed using MD Solid software (MDSolids: Educational Software for Mechanics of Materials 2020)
Discussion
Based on the MD Solid software, T-shape beams show the both principal and centroid axes. The T-beam has an elastic modulus shape that can directly fit entered directly any common material. The elastic modulus value is 73 GPa. Here, the user is capable of rotating the shape to the desired orientation from display buttons, for instance, rotating the T beam stem to points upward. This property will enable users to ensure the orientation exactly match a particular structural problem that needs a solution. Also, there are slabs one side of the end beam acting as T-beams. Generally, as was discussed in the introduction, reinforced concrete structures are cast monolithic. Therefore, for a structural section that is made of several monolithic cast beams, T-beams are always the intermediate beams. For instance, in the flooring system, T-beams can be used together with the L-beam for reinforcement.
The T-beam has shape factor of 1.2216, which explains why the angle ratio under which its two surfaces are appearing is zero regarding one another. This shape factor is useful in computing the heat exchange that may arise a result of isothermal knot parameterization, light engineering, and thermal radiation in space thermodynamics. So, L-beams are subjected to bending moment, shear force and torsional moment. Changes in floor level may be accommodated by either an L- beam or by building up one side of an inverted T-beam, as shown in Figure x. Based on the T-beam properties from table above, the equal T-beam Moment of Inertia related in the z-axis equals 32,904,100 mm4 (Iz), while in the polar Moment of Inertia in the z-axis being 41,860,700 mm4 (Iz). The unequal T-beam area shape is 4,480 mm2 with an Elastic Modulus (E) of 73GPa. A flooring system with multiple monolithic cast beams with the slab can have the T-beam acting as an intermediate beam with the other corner beams or corner walls forming the L-beams. As such, the both the L-and T-beams can be used together in the floor system as illustrated below.
Fig. 7: Combined T- and L-beams for a floor system (Hamakareem, 2020)
Fig. 8: Application of T-beam in real life (Yu, 2020)
Conclusion
In summary, the actual model of T-beam structure was prepared after determining various properties of both equal and unequal beams. The properties determined were then displayed as shown in Fig. 6 with a screenshot obtained from the MD Solids software. The objective of the lab experiment was achieved by learning how to apply as well as design various shapes of beams using 3D AutoCAD.
References
Ching, F.D.K. (1995). A Visual Dictionary of Architecture. New York: John Wiley and Sons. p. 203. ISBN 978-0-471-28451-2.
Hamakareem, M. I. (2020.). 21 Types of Beams in Construction . Retrieved from The Constructor: https://theconstructor.org/structural-engg/types-beams-construction/24684/
MDSolids: Educational Software for Mechanics of Materials. (2020). Retrieved 16 April 2020, from http://web.mst.edu/~mdsolids/sectionprops.htm
Oda, J., Akimoto, K., & Tomoda, T. (2013). Long-term global availability of steel scrap. Resources, conservation and recycling, 81, 81-91.
Paramasivam, P., Lee, S. L., & Lim, T. Y. (2017). “Shear and moment capacity of reinforced steel-fibre-concrete beams”. Magazine of Concrete Research. 39 (140): 148–160. doi:10.1680/macr.1987.39.140.148.
Shreedhar, R., & Mamadapur, S. (2012). Analysis of T-beam bridge using finite element method. International Journal of Engineering and Innovative Technology, 2(3), 340-346.
Sidhu, J. S. (2008, December 4). L- beams or flanged beams . Retrieved from SlideShare: https://www.slideshare.net/honeysid/l-beams-or-flanged-beams-presentation
Yu, X. (2020). Prestressed T-beam forming machine. Retrieved 16 April 2020, from http://www.xingyumachine.com/T-beam-machine/