Applications of shape memory alloys in civil engineering structures—Overview, limits and new ideas

Abstract

Shape memory alloys (SMAs) are metallic materials with great potential to enhance civil engineering structures. They are often referred to as smart materials. A basic description of their highly non-linear material behaviour in terms of shape memory effect, superelasticity, martensite damping and variable stiffness is given in this aiticle. It is followed by a brief introduction to Ni-Ti and Fe-Mn-Si SMAs. Preexisting and new applications in the fields of damping, active vibration control and prestressing or posttensioning of struchues with fibres and tendons are being reviewed with regard to civil engineering. Furthermore, the relatively high costs ai1d the problem of retaining posttensioning forces when using some types of SMAs are nained. In this regard is Fe-Mn-Si-Cr discussed as potential low cost SMA. A simple model for calculating the activation times of resistive heated SMA actuators or springs is presented. The results and measured data lead to fmther constrictions. Finally, new ideas for using SMAs in civil engineering structures are proposed in this aiticle such as an improved concept for the active confinement of concrete members. This article is to introduce civil engineers to the world of shape memory alloys and invite them to contribute to their wider use in civil engineering structures.

Defects of Communication Pipes from Plastic in Modern Civil Engineering

“…Works [1][2][3] are devoted to a communication research between processing parameters both technological and operational properties of the received polymeric materials and also solutions of the tasks connected with application and fastenings of polymeric pipes are considered. Authors describe ways of plastic products connection and key parameters for calculation of building constructions from plastic.…”

“…Depending on the nature of the transformations happening to polymer at his processing in a product are subdivided into thermolayers (the most important of them -plastic on the basis of polyethylene, polypropylene, polystyrene, polyvinylchloride, polyamides, polycarbonates, a politetraftoretilen) and reaktoplasta (the most largecapacity look -phenoplasts, are widely used also plastic on the basis of epoxy resins, polyester pitches, the kremniyorganicheskikh of polymers, etc.) [1][2][3]. In modern civil engineering exclusively corrosion-proof materials are applied to laying of new communication systems: plastic pipes, polyvinylchloride pipes (PVC), products from polypropylene, corrugated analogs, etc.…”

Feasibility of shape memory alloy in a tuneable mass damper to reduce excessive in-service vibration

“…SMA has superior mechanical characteristics compared to conventional materials, such as large recoverable deformation, high damping capacity and solid-solid phase transformation ability [7][8][9][10][11].…”

Thermodynamic properties and microstructures of different shape-memory alloys

“…Alloys based on nickel (Ti-Ni, Ni-Mn-Ga) 2. Alloys based on copper (Cu-Zn-Al, Cu-Zn-Si, CuZn-Sn, Cu-Zn-Ga, Cu-Zn-Mn, Cu-Zn-Al-Ni, Cu-ZnAl-Mn, Cu-Al-Ni, Cu-Al-Be, Cu-Al-Mn) 3. Alloys based on iron (Fe-Mn, Fe-Ni-C, Fe-Mn-Cr, Fe-Mn-Si, Fe-Ni-Nb, Fe-Co-Ni-Ti) 4.…”

“…The interest in SMAs is continuously increasing as new areas of application are discovered. Today, SMAs are used in different areas such as civil engineering 3,4 , the production of microsystems 5 , medicine [6][7][8] , earthquake technologies 9-11 and robotics 12,13 .…”