Vibrations which have been caused by non-seismic factors as high-speed rails, highway traffic, construction activities, machine foundations, blasting, underground explosions, etc. have not been considered safe for human life and structures around. Vibrations which have been generated by these sources have caused of occupant discomfort, settlement and shaking of building foundations, structural and non-structural damages to adjacent buildings, malfunctioning of ultra-sensitive medical equipment, etc. Vibration screeners in form of open or in-filled trench wave barriers have been used to reduce the effects of vibrations. This paper has described an experimental study for evaluating the performance of in-filled materials in trench wave barriers in an elastic, homogeneous and isotropic half space. The in-filled materials used are as rice husk, crumbed tyre rubber and sawdust. Key properties of the in-filled materials are have also been determined by geo-technical characterization to ascertain its suitability in terms of properties of in-filled materials. The important factors such as material damping and boundary conditions of soil have also been included. The effectiveness of geometric dimensions of the trench wave barrier, shear wave velocity and location of source from the barrier have also been investigated. In this study, a dimensionless approach have been used, where the geometrical parameters have been normalized by one of the characteristics i.e. wavelength of Rayleigh oscillatory wave in elastic half-space. The influence of parameters related to vibration isolation has been discussed in detail. Recommendations have been provided for the optimal selection of the geometry of trench wave barriers.
In high-rise buildings shear walls have performed very effectively as lateral load resisting system. Similar to columns, shear walls being generally subjected to flexure with axial forces should have been designed by P-M interaction charts obtained from the concept of capacity-based-approach. Following the design provisions of IS 456:2000,P-M interaction charts for RC slender rectangular shear walls have already been reported depicting failures within the domain of compression-bending. However, shear walls under seismic effects may fail in tension. In the present work P-M interaction charts have been proposed for slender rectangular shear walls for the entire domain of failure right from pure compression to pure tension following the design provisions of IS 456:2000. Quantification of ductility values to assess the seismic performance of shear walls designed as per Indian standards have been very scarcely reported. In the present work curvature ductility of rectangular shear walls have been quantified following the fundamental principles of Limit State Method and presented in the proposed P-M interaction charts. This can enable designers to assess the strength and ductility of shear walls simultaneously. The present study has indicated that ductility of shear wall failing in pure bending has been found to be maximum when designed with minimum percentage of vertical reinforcement (0.25). Damage assessment of shear wall sections as per Performance-based Criteria of ASCE 41-13 has indicated that the minimum vertical reinforcement percentage (0.25%) specified in IS13920:2016 requires modification to restrict the damage within the collapse prevention stage.
This research paper has presented the design, numerical analysis, and experimental validation of a bio-inspired morphing airfoil actuated through shape memory alloy (SMA) wire and spring elements. To facilitate controlled deflection, a corrugated morphing section has been embedded within an eppler airfoil, which has been selected through comparative aerodynamic analysis against a standard NACA 0012 profile. Finite element simulations have been conducted using ANSYS software to investigate tip deflection performance across varying morphing region lengths and actuator placements. A lightweight, three-dimensionally printed prototype incorporating shape memory alloy components has been developed and has been thoroughly evaluated using direct electrical heating methods. Experimental findings have shown a 4 mm downward deflection for a 1 mm actuator wire contraction, which has closely matched the numerical simulation predictions. To demonstrate scalability, a full-span wing prototype has been assembled utilizing three independent, actuated airfoil segments. The successful actuation of this system has validated the feasibility of shape memory alloy-driven morphing as a viable, lightweight alternative to traditional servo-based mechanisms in micro air vehicles and low-speed unmanned aerial vehicles. Furthermore, this research has established a practical foundation for future work aimed at enabling bi-directional actuation for enhanced aerodynamic control and maneuverability.
The ADC (Analog to Digital Converter) has become essential for interfacing analog signals with the digital domain, particularly in applications requiring high resolution and low voltage operations. Recent advancements in technology have led to reduced signal power and voltage through supply voltage scaling, which has posed significant challenges for ADC performance, including increased area, narrow input range, and process variation. To address these issues, this study has proposed a VCO (Voltage Controlled Oscillator)-based ADC integrated with an ACO-PSO (Ant Colony Optimization- Particle Swarm Optimization) algorithm, thereby enhancing stability, reliability, and effectiveness in chip design. The proposed system has utilized real-time input sources, specifically solar PV (Photo Voltaic) and wind energy, and has incorporated a SEPIC (Single-Ended Primary Inductance Converter) to deliver a controlled output voltage. The ACO-PSO algorithm has optimized the values obtained from the VCO-based ADC and has selected the best solutions to achieve improved performance. The efficiency of the framework has been assessed by measuring gain and delay through Verilog simulations, and the results have been obtained using MATLAB/Simulink. The circuit has occupied an area of 0.012 mu m2 and has achieved a Mean Square Error (MSE) of 0.2 and a Peak Signal-to-Noise Ratio (PSNR) of 52 dB, thereby demonstrating superior efficiency compared to conventional methods.
The Belanger equation has been found to be inadequate for predicting sequent depth in hydraulic jumps occurring on rough, sloping channel beds. To address this limitation, a roughness Froude number incorporating the effects of bed roughness and channel slope has been introduced in this study. Three sets of experimental runs have been conducted in a channel flume using three bed roughness values (0.0256 m, 0.0387 m, and 0.0438 m) and three adverse slopes (-0.025,-0.030, and-0.035). The resulting datasets have been used to tabulate sequent depth and jump length and to develop two regression-based semi-empirical relationships relating the roughness Froude number to the sequent depth ratio and the relative jump length, respectively, for hydraulic jumps on adverse slopes. The proposed equations have been validated against experimental observations and have shown agreement within deviations of 30% for sequent depth and 33% for jump length.
