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Several reasons result in the need for retrofitting of existing reinforced concrete structures, and extensive effort is devoted to invent and implement different methods for strengthening RC members. One of the leading rehabilitation techniques is attaching FRP strips, but FRP materials’ low ductility has caused several issues such as FRP-structure debonding, boundary layer cracking, and brittle behaviour of the strengthened RC members. To overcome these drawbacks, the Smart Plate (SP) which is a ductile retrofitting cover, is proposed for the first time. This cover is formed by embedding Shape Memory Alloy (SMA) wires in an elastomeric substrate. The SMAs exhibit certain properties, including superelasticity, shape memory effect, and tem
Regarding the importance of bridges as one of the most critical infrastructures, their maintenance, and health monitoring is of high priority. Interaction between the moving vehicles and bridges is amongst the fields of study that have been investigated in depth by numerous researchers in the field of bridge engineering. Among different proposed methods of structural health monitoring of bridges, the indirect methods that do not need the healthy structure response are of high interest because of their ease and low maintenance costs.The response of a moving mass passing through a bridge can be analyzed for the indirect prediction of the beamchr (chr ('39') 39chr ('39')) s mechanical properties. This can lead to the detection of possible dama
This article presents an investigation on the durability of different glass-fibre-reinforced polymer composites when subjected to harsh outdoor conditions, including freeze/thaw cycles, ultraviolet radiation and moisture, as well as when used with seawater sea-sand concrete for construction applications. To achieve this, the effects of a number of parameters, including the environment of exposure, exposure time, profile cross-sectional configuration and orientation of fibres, on the mechanical properties of different glass-fibre-reinforced polymer composites were studied. To investigate the degradation of the mechanical properties, three-point bending, compression and tension tests were conducted on both reference and conditioned samples. M
In this research, the mechanical properties of various glass fibre reinforced polymer (GFRP) pultruded profiles exposed to seawater sea sand concrete (SWSSC) and its combination with UV radiation and water vapour condensation were studied. The effect of different conditions, duration of conditioning, and the profile cross-section configuration on the mechanical properties were investigated. Three-point bending, tension, and compression tests were carried out to obtain the mechanical properties, including flexural, tensile and compressive strengths and tensile elastic modulus. Furthermore, in order to scrutiny the mechanisms and extent of damage, scanning electron microscopy (SEM) was carried out on the test samples before and after the expo
In this paper, a metallic yielding damper, called piston metallic damper (PMD) is introduced for the first time. The PMD is comprised of a set of parallel hollow circular plates that interconnect inner shaft of the PMD to its outer pipe. Experiments and numerical models are used to examine its applicability as a seismic energy dissipating device. In this novel damper seismic input energy will be dissipated through flexural yielding of circular steel plates when system experiences small to medium displacements. At large displacements, tensile behavior will dominate and causes significant increase in stiffness of the system. In experimental program, different specimens were tested and the hysteretic behavior was recorded. These experiments in
Given the key importance of the bridges in transportation system lifelines and due to their high initial cost, there is a constant need for the study and monitoring of such structures. The FRP composites, due to their special characteristics including high specific modulus, high specific strength, corrosion resistance, low mass density, and modular construction, can be a good alternative for common bridge deck systems. Too much effort is devoted to implement FRP materials as a whole or in part in bridge construction. There have been several different methods of using FRP materials in bridges, including FRP stay-in-place forms for concrete decks and whole FRP bridge decks. Bridges constantly bear moving mass loads while due to technological
In the current research a statistical micromechanical approach for the determination of the mechanical properties of composite materials is proposed. The proposed method is mainly based on the well-known periodic homogenization scheme. The methodology implements multi-step multiscale approach to calculate the mechanical properties of composite materials where the statistical characteristics (e.g. size, aspect ratio, orientation) of the reinforcing phase are known as probability distribution functions (PDF). The calculations start from Unit Cell I which resembles the microstructure of material at the lowest length scale and continue until the largest fiber is considered in the final unit cell setting. The results of the presented theory are
Research on microstructure of main engineering materials revealed that some of these materials exhibit similar microstructure patterns at different length scales. Since these patterns are replicated at different length scales the whole microstructure can be viewed as a set of periodic substructures. Homogenization technique for periodic microstructures has found many applications in simulation of composite materials by considering the geometry of fibers distribution. In this study a homogenization technique for periodic microstructures is developed. In this generalization a multi-step homogenization is being used. In each step of homogenization the geometry which is coincident with the true microstructure is produced to maintain the propert