Smart Materials and Their Applications in Civil Engineering - Coursework Example

SMART MATERIALS AND THEIR APPLICATIONS IN CIVIL ENGINEERING by Smart materials exist in different temperatures and in two phases. The first is Marten site that exists at low temperatures and Austenite that exist in high temperatures. Change in external temperature and stress condition influences the two phases to change into another phase. This however depends on what change appears. They show many unique properties during this transformation such as super elasticity and shape memory. Smart materials fields are rapidly emerging with technological innovations in engineering actuators and image processing. Smartness describes memory and self-adaptability of structure sand materials. Smart materials have many uses. Structures such as pipelines ships and aircraft must be actively designed to prevent tearing out. This paper will discuss the use of smart materials in civil engineering. Introduction The introduction of material science came about with much high quality, new and self-efficient materials that came into use in the field of structural engineering. One good example is smart materials. Nickel Titanium, for instance, was first studied in Naval Ordinance Laboratory and was rapidly used in many fields such as biomedical, aerospace and mechanical engineering. More smart materials are being researched on due to their performance in civil engineering applications. Smart materials have been considered as significant components in the improvement of structures developed by civil engineering. Main Text Smart materials have brought about different applications in civil engineering in recent times. An example of a smart material used in civil engineering is the shape memory alloy (SMA) that has several characteristics such as shape memory effect and super-elasticity. As such, the SMA has been used to control structures in civil engineering. The development of cost effective and durable materials used for construction has been improved by the introduction of smart materials, such as piezo-electric materials, carbon fibre reinforced concrete and smart bricks among others. Fiber Reinforced Plastics (FRP) Structures made out of civil engineering could be damaged by factors such as floods, earthquakes and other natural disasters. However, the use of fibre reinforced plastics (FRP), an example of smart materials helps to ensure that damaged structures are repaired cost effectively and durably. Today, Fibre reinforced polymer composite (FRP) is used as a new construction material by civil engineers. Bridge engineering is one of the fields that has actively increased the use of FRPs because the materials introduced by this polymer have high tensile strength to weight ratio, therefore, being advantageous than traditional materials. In addition, this material can be modelled into various shapes and has the ability to resist poor environmental conditions, which results to low maintain costs. Therefore, this offers bridge structures durability and low cost of maintenance proving FRPs advantage compared to other non-smart materials (Tuakta, 2005:2). Investigations into the use of Smart Materials in Civil Engineering In civil engineering, the smart materials are used to monitor structures and analyse their durability. The smart materials are restricted to sense and adapt to the environment to ensure that the structures put up can be responsive to the environments they occupy. The use of smart materials in civil engineering can also be used in concrete masonry walls. According to Tomazevic & Weiss (1994), the reinforcement of the masonry walls by vertical reinforcement especially at the borders of the walls and horizontal reinforcement in the mortar bed joints, the lateral resistance improves by a larger margin (Tomazevic & Weiss, 1994:324). Smart materials can be used to replace concrete masonry units (CMUs) that are hazardous even though they are used to build external walls of panels of structures (Baylot, Bullak, Slawson & Woodson, 2005:1186). Since 1995, the Air Force Research Laboratory (AFRL) in Florida has researched the development of lightweight methods of retrofit strengthening structures meant for blast loading. The research revealed that the use of smart materials improves the quality of the structures and the subsequent durability. As such, it shows that smart materials have become essential in civil engineering. Mullians, Sen, Suh & Winters (2005) investigated the application of FRP on underwater repair of corroding pre-stressed piles through a field demonstration study. The results of this study revealed that instrumentation using FRP allowed the corrosion potential to be determined especially over the unwrapped surface of the piles and for the wrapped piles (Mullians, Sen, Suh & Winters, 2005:143). The study indicated that surface preparation was essential in controlling corrosion and that underwater wrapping is a visible system. This showed the ability of smart materials to evaluate corrosion levels and help civil engineers make appropriate decisions with respect to the repairs or replacement of piles to ensure that significant damage is not caused. Smart Materials in Storey Buildings Multi-storey buildings have shear walls that serve as resisting systems especially around elevator shafts and stairs. However, these shear walls never satisfy this purpose because of their ductile behaviour conditions. This has been disadvantageous to such buildings because they have mostly been destroyed by earthquake occurrences. The damages include shearing, bending, overturning and sliding damages all of which occur during earthquake occurrences. SMA has been used to lessen the damage of earthquake occurrences because of its unique characteristics, for instance, energy dissipation, super-elasticity and memory effect as shown in figure 2. As such, SMAs have attracted attention is passive control structures developed through civil engineering practices. For instance, Dolce & Marnetto (2000) investigated the effectiveness of SMA materials that are used in seismic applications. From the results of the study, the authors proposed the use of various forms of SMAs for special dampers in different structures (Dolce & Marnetto, 2000:945). Discussion The use of smart materials in the engineering fields has been increasing overtime. Smart materials also sense their environment and respond, and are constructed from a single material. They may incorporate smart materials and might be built using a traditional technology. Pacemakers are a smart system that is designed to respond to an irregular heartrate. This is made possible by an electrical impulse that regulates it. The fields include shock absorption, shock control, actuators, biomedical areas, composites and automatic on and off switch. Smart materials are having also been successfully adopted as load bearing actuators in some complex structures (Baylot, Bullak, Slawson & Woodson, 2005:1186). These include submersibles, rotor blades, and aircraft wings. Numerous investigators are also carrying out the research of an underwater vehicle that shares the agility and hydrodynamic efficiency of aquatic animals. Smart materials have the abilities to change their properties like damping, internal forces, and young modulus. The smart material has been integrated with this feature to implement control for dynamic and static performance. It was reported that the smart materials features could be well adjusted.This meant that static and dynamic elements of composite materials could be set such as maximum shape and deflection. In civil engineering, smart materials are used for a variety of purposes. They are used in the control of structures, ensuring their durability and effectiveness and increasing the safety of the occupants of structures, such as storey buildings in times of earthquakes. They have proved to be of significant help in a variety of ways all of which are beneficial to structural engineering. The materials are also used in the field of structural engineering. They are used to control the civil engineering structures to evaluate their durability. Smart materials are not only restricted to sensing, but they also adapt to their surrounding environment such as the ability to move and vibrate too. The uses of such adaptive materials involve the capability to monitor the aero-elastic form of the aircraft wing to improve and pull operational efficiency. This is to control the vibration of satellites and lightweight structures. Structural integrity in aircrafts is also being controlled by the materials. More research is needed to investigate certain piezoelectric materials to minimize noise in air conditioners. The materials are also used to monitor the integrity of dams, bridges where sensors are used in the structures to identify troubled areas (Mehdi, Mohammad, Seyed & Seyed, 2012:34). Smart materials are materials of the new generation that are surpassing the conventional structural and functional materials. The have adaptive capabilities to the external stimuli such as environment or load with inherent intelligence. Smart materials can also be defined as a device that can sense changes in its environment. It can also make optimal responses by changing its properties mechanical, geometrical and material properties. The sensor and actuator functions with their appropriate respond must be properly integrated. They can also be defined as materials that respond to changes of the environmental changes at most optimum conditions. They are categorized as either active or passive. More new and high-quality materials are coming with the development of engineering (Cai, Wu, Chen & Voyiadjis, 2003:20). One smart material is Nickel Titanium that is used in many fields including the fields of biomedical engineering. Smart materials exist in two phases in terms of temperature. That is Marten site and Austenite. Some of the areas where smart materials are used are structural engineering, health, Reduction of waste and structural health monitoring. In structural health engineering, embedding sensors are installed to monitor stress and damage to structures. Smart materials are not only restricted to sensing but also are also adapted to surrounding environment such as ability to move and make vibrations. The materials also control the integrity of bridges and dams. In the biomedical field, some materials like poly electrolyte gels are being experimented with muscle applications In the reduction of waste the use of manual disassembly is expensive and time consuming but the use of smart materials makes the process could make the process more efficient. In health, Biosensors made from smart materials could be used to monitor the blood sugar level (Cai, Wu, Chen & Voyiadjis, 2003:33). Conclusion The technology of smart materials is a highly interdisciplinary field. Beginning from the area of basic sciences such as physicist also covers the applied sciences such as aeronautics and mechanical engineering. This may explain the slow progress of smart materials in the engineering systems. In civil engineering, smart materials have provided an effective way of ensuring that structures are durable and are effective for their purposes. It also ensures that structures can resist environmental aspects such as earthquakes and the damages that they cause, thereby preventing the destruction of property and loss of lives. Smart materials offer advantages over the other conventional materials used in civil engineering. Controlling and understanding the microstructure and composition of any new materials are the ultimate objectives of research in this field and is important to the production of good materials. The scope of application of smart materials includes solving civil engineering problems with unfeasible efficiency. They provide an opportunity for creation of new products that generate income. As far as technical applications of these materials are concerned, it also involves composite materials embedded with fibre optics. The kind of smartness exhibited by these materials is generally programmed by special processing, introduction of defects or by material composition. Other than civil engineering, smart materials are used in space systems, automobiles fixed, rotary wing aircrafts machine tools, and medical devices. The feedback functions within the materials are combined with functions and properties of the materials. Other applications of smart materials are still being processed. Tables and Figures Figure 1 Figure 2 Reference List Baylot, J.T., Bullak, B., Slawson, T.R, & Woodson, S.C., 2005. Blast Response of Lightly Attached Concrete Masonry Unit Walls, Journal of Structural Engineering, ASCE, 131(8), August, pp.1186-1193. Cai, S. C., Wu, W., Chen, S., & Voyiadjis, G., 2003. Applications of Smart Materials in Structural Engineering (No. LRTC Project No. 02-4TIRE). Louisiana Transportation Research Center. Dolce, M., Cardone, D., & Marnetto, R., 2000. Implementation and testing of passive control devices based on shape memory alloys. Earthquake engineering & structural dynamics, 29(7), 945-968. Mehdi, G., Mohammad R. B., Seyed, M. G., & Seyed, A. N., 2012. Improvement of Concrete Shear Wall Structures by Smart Materials. Open Journal of Civil Engineering. Mullians, G., Sen, R., Suh, K., & Winters, D., 2005. Underwater Failure-Reinforced Polymers Repair of Pre-stressed Piles in the Allen Creek Bridges, Journal of Composites and Construction, ASCE, 9(2), April, pp. 136-146.  Tomazevic, M. & Weiss, 1994. Seismic Behaviour of Plain and Reinforced Masonry Buildings, Journal of Structural Engineering, ASCE, 120(2) February, pp. 323-338. Tuakta, C., 2005. Use of fiber reinforced polymer composite in bridge structures (Doctoral dissertation, Massachusetts Institute of Technology). Read More