Indian Journal of Engineering and Materials Sciences (IJEMS)

Critical review of codal provisions on the torsional irregularity

Jawahar Prakashvel, Chockkalingam Umarani, Kannaiyan Sathish Kumar — Fri, 07 Nov 2025 00:00:00 +0530

Buildings with irregularities have consistently been highly vulnerable to seismic events. The earthquake events have been showing the failure patterns of the reinforced concrete buildings with various irregularities. But the large number of buildings have been existing and being constructed with irregularities both in the urban as well as rural areas of developing countries. Various irregularities have been defined in international standards. But still, there is a need to study the combined irregularities of the building. In this study, the various country codal provisions on torsional irregularities in the reinforced concrete buildings have been reviewed and compared. Most of the codes have considered the edge displacements as the measure of torsional irregularity criteria. The amplification factorshave been used for structural eccentricity and accidental eccentricity to increase the design forces. The torsional flexibility based on the ratio of the natural period of torsional mode
and translational mode, stiffness eccentricity ratio, and the mass factor based on the radius of gyration of mass about the center of mass of the building have been introduced in the draft code IS 1893-2023, Part-2. The limiting value have been prescribed by the code for torsional flexibility factor to prevent the failure of buildings due to torsional flexibility. In this paper, various significant factors affecting the seismic performance of the buildings due to torsional irregularity have been reviewed.

Investigation of an electroplated NixFey film for magnetometer applications

Aditi, Supriyo Das, Ram Gopal — Fri, 07 Nov 2025 00:00:00 +0530

This paper has investigated the development of a Microelectromechanical System (MEMS)-based magnetometer utilizing the Ultraviolet-Lithographie, Galvanoformung, Abformung (UV-LIGA) technique, with a structural layer composed of nickel-iron (Ni_xFe_y) alloy. Earlier implementations of MEMS magnetometers using pure nickel as a structural material encountered challenges due to high residual stress, leading to performance degradation and mechanical instability. To address this, an optimized composition of Ni (87%) and Fe (13%) is employed to minimize residual stress and enhance the structural integrity of the device. The proposed magnetometer is fabricated on a boro-float glass substrate, chosen for its low parasitic capacitance and reduced requirement for passivation layers. The design incorporates a novel resonant structure with support arms positioned at the extreme ends of the beam, maximizing the overlap area between movable and fixed electrodes for improved sensitivity. The device operates based on Lorentz force transduction, where an excitation current applied at the resonant frequency interacts with an external magnetic field, inducing vibrations. Extensive experimental investigations were conducted to optimize the electroplating process and reduce stress. Elemental analysis of the NiFe film was performed using energy dispersive spectroscopy (EDS) to verify the composition, The mechanical sensitivity of the device was measured as 237 pm/Gauss at atmospheric pressure using a Laser Doppler Vibrometer (LDV), demonstrating its high-performance capabilities. This work reports a novel MEMS-based Lorentz force magnetometer with Ni₈₇Fe₁₃ as the structural layer, fabricated using the UV-LIGA process. The study establishes a reliable methodology for the development of stress-free, high-sensitivity magnetic sensors, contributing to advancements in miniaturized sensing technologies for applications in navigation and industrial automation.

Development of porous composite matrix using fly ash, waste tyre rubber, and rice husk ash for sustainable engineering applications

Abhishek Bisarya, Krishnakumar Bhaskaran, Ritesh Vijay — Fri, 07 Nov 2025 00:00:00 +0530

Utilization of Fly Ash (FA), Waste Tyre Rubber (WTR) and Rice Husk Ash (RHA) has grown as research towards handling the disposal issue and its environmental degradation concerns. The present research and development has delineated a sustainable porous composite matrix utilizing industrial and agricultural wastes with minimal content of cement and water. The research study has includes three phases of development like FA-Cement; FA-WTR-Cement and FA-WTR-RHA-Cement. Two optimized matrices FA-WTR-RHA-Cement (50%+20%+10%+20% and 50%+15%+15%+20%) by weight exhibited density 1.4 g/cm³, compressive strength of 8.0 and 8.8 MPa and system porosity of 61% and 60.5% respectively. FESEM and EDX further validated a stable internal microstructure characterized by well-integrated waste particles, thereby improving the functionality of the matrix. A leachability study has also carried out on the optimized matrices with results well below the regulatory levels. Overall, the developed composite offers a low-carbon, eco-friendly alternative to traditional materials, without any chemicals/additives, pre and post-treatment of the waste for sustainable civil and environmental engineering applications.

Non-destructive assessment of heat-damaged concrete

Aparna Chaturvedi, Mahesh Gaikwad, Nawal Kishor Banjara, Suvir Singh — Fri, 07 Nov 2025 00:00:00 +0530

The damage assessment of concrete exposed to different temperatures has been essential to ensure structural safety and residual behavior. High temperatures have significantly weaken the integrity of concrete, which may have lead to partial or complete failure of concrete elements under loading conditions, posing safety risks. To investigate the extent of damage caused by high temperatures, an experimental study has been conducted involving visual inspection and non-destructive testing. Concrete cubes have been exposed to elevated temperatures under steady-state heating conditions, and the UPV test has been performed after they have been completely cooled to ambient conditions. Based on the test findings, a temperature-dependent relationship has been established for UPV velocity and transit time. The test results have indicated that cubes exposed to elevated temperatures exhibit a significant reduction in UPV values compared to unexposed cubes, with the extent of damage having increased with temperature. Developed temperature-dependent equations have aided in determining the quality of concrete after exposure to various temperature ranges. This study has aided in understanding the degree of damage at elevated temperatures.

Performance evaluation of different shape and orientation of digging blades in soil bin

Narender, Atul Kumar Shrivastava, Ajay Kumar Roul, Parmod Sharma — Fri, 07 Nov 2025 00:00:00 +0530

This research has optimized the shape of digging blade with the relationship between speed, rack angle and depth. The effect of speed, rack angle and depth of blades (triangular fork, V shape, convex and rectangular) on drafts has studied experimentally for the speed (2.06, 2.9 and 4.18 km/h), rake angle (15°, 20°, 25°) and depth of operation (10, 15, 20 cm) in a soil bin. The study has conducted in the soil bin to finalize the design of digger blades for minimum draft for the root zone depth of turmeric and ginger crops. Response surface methodology (RSM), a mathematical modelling technique has used for design experiments, statistical evaluation, and optimization of parameters. The mean values of the vertical and horizontal draft at different forward speed and depth of operation have increased with the increase in the rake angle of all four types of blades in the soil bin. The average minimum vertical draft has found to be 2.167, 2.987, 5.867 and 4.057 kgf at 15° rake angle and maximum of 26.967, 26.527, 42.473 and 89.533 kgf at 25° rake angle for triangular fork, V-shape, convex, and rectangular shape of blades, respectively. The average minimum horizontal draft has found to be 58.36, 59.317, 65.95, and 38.71 kgf at 15° rake angle and maximum of 153.517, 170.943, 183.82 and 241.67 kgf at 25° rake angle for V-shape, convex, rectangular and triangular fork shape of blades, respectively. The overall mean draft has found to be maximum in triangular fork shape blade and minimum in V-shape blade which can be used for performance evaluation of the digger in the field.

Significance of ductility on aseismic design of flexural members for normal to high strength concrete

Bibhas Mandal, Santanu Bhanja — Fri, 07 Nov 2025 00:00:00 +0530

The standards or codes of practice of different countries set limits on the minimum and maximum longitudinal reinforcement in beams. On evaluation of the design parameters of these limiting sections, behavior of all sections in flexure can be assessed, as they will lie within the domain of these two conditions. The present study has been directed towards assessment of the behavior of flexural members up to and beyond limit states in accordance with the provision of different standards. IS:456-2000 being more than twenty-four years old seems to be outdated w.r.t the present-day material properties and design provisions whereas these have been covered in a befitting manner in IRC:112-2020 which is in line with international standards. Load based prescriptive method of design ends at design load levels and cannot provide any solution for design beyond the design loads either due to overloading or due to larger deformations which can lead to considerable damage or even actual collapse. For this the damage level of the sections at different performance-based limit states beyond the limit state of collapse need to be assessed as per the provisions of Performance Based Design (PBD). In the present work a comprehensive study on the curvature ductility and deformation levels of sections in flexure as per IRC:112-2020 have been performed and compared with the acceptance criteria as per international guidelines and standards.

Developing an integrated clustering algorithm based on fuzzy C-means for characterizing sound signals of vibration test rig

Fri, 07 Nov 2025 00:00:00 +0530

Fuzzy-based integrated clustering application, or FICA, has been developed in this research. It effectively performs data clustering by considering seven clustering quality indexes, namely the partition coefficient, classification entropy, modified partition coefficient, Fuzzy silhouette width, Xie-Beni, partition index, and separation index, leading to more optimal cluster results. In addition, FICA is also equipped with correlation coefficient and coefficient of determination functionalities that describe the relationship in the clustered data. For validation purposes, a data set of 30 sound signals with sampling frequencies ranging from 11-20 kHz has been measured with a voltage of 6, 9, and 12 Volts for 30 seconds. Similarly, key parameters such as sampling frequency, sound pressure level, and power spectral density have been obtained from sound signals and have been clustered and compared with open-source software. Validation results have shown that only Fuzzy silhouette width reports different results, although the difference does not affect the selection of the optimal number of clusters. Both FICA and the software has recommended the same number of clusters, which was 2, for the two and three dimensions. In conclusion, an integrated, user-friendly, and accurate clustering application for engineering data has been successfully developed.

Formulation and analysis of novel hybrid material for shock wave endurance with integrated image processing techniques

Pradeep Kumar S L, Maniraj Jaganathan — Fri, 07 Nov 2025 00:00:00 +0530

The growing demand for protective materials in high-stress environments, such as bomb squad suits, fire-resistant suits, and the oil and gas industry, has rendered their development more critical. Existing solutions have not succeeded in achieving a cohesive integration of structural integrity, thermal stability, and vibration dampening. This study addresses this gap by examining the shock wave penetration resistance of silica aerogel, sorbothane, and graphite composites. We used ANSYS to conduct simulations on the individual materials and six composite configurations to evaluate their mechanical properties in comparison. A high-pressure shock tunnel has been used to assess shock wave effects, while Scanning Electron Microscopy (SEM) has been utilised to examine the consequences on microstructure. Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), and image processing techniques have corroborated the results. The findings demonstrate that silica aerogel and graphite possess considerable strength, whereas sorbothane excels in vibration absorption. The SEM analysis indicates that their porous, clustered, and interplanar characteristics enhance their shock resistance. Combination 1 has shown superior performance among all composites, exhibiting excellent thermal stability under shock-inducing loads. This study demonstrates that the silica aerogel–sorbothane–graphite composite exhibits a synergistic equilibrium of mechanical strength, thermal resistance, and vibration attenuation, making it suitable for advanced protective applications.

Preparation and characterization of hydroxyapatite reinforced polymeric scaffolds

Fri, 07 Nov 2025 00:00:00 +0530

Porous HA reinforced PLA/PCL scaffolds with polymer volume percentages in the 7.0–7.6 range have been prepared by solvent-casting/salt leaching technique. The scaffolds have been characterized by conducting gravimetric measurements, FTIR analysis, TGA, X-ray diffraction analysis, compression tests, cell viability tests, and thermal and hydrolytic degradation tests in order to investigate the effect of PLA/PCL, PLA/HA, PCL/HA and PLA/PCL/HA blending on scaffold properties. Porosity of the scaffolds has been determined to be in the 83–92 percent range. The scaffold porosity has decreased with HA content. The water absorption of the scaffolds has been found to be in between 400 and 750%. The yield strength and the elastic modulus of the scaffolds have been determined to be in the 0.001–0.02 and 5.6–10.6 MPa ranges, respectively. The yield strength of the scaffolds has increased by both PCL and HA contents whereas elastic modulus has increased with PCL content but has decreased with HA content. Mechanical test results have indicated that the addition of HA has increased the strength of the scaffolds while decreasing their flexibility. The activation energies for the thermal degradation of the scaffolds have been determined to be in the 130–398 kJ/mol range and have been shown to be a function of PCL, PLA, and HA content. The hydrolytic degradation behavior of the scaffolds in acetate buffer solutions (pH=4.5) during 127 days and XRD analysis have indicated that the hydrolytic degradation occurring in the amorphous part of the surface film has been diffusion-controlled. The diffusion coefficients of the degradation products in the scaffolds have been estimated to be in the 1.21–4.95×10⁻¹³ m²/s range. Cell viability test results have indicated that the composition of the composite scaffold structure has played a determining role in
the prepared scaffolds.