Effects of variable resistance on smart structures of cubic reconnaissance satellites in various thermal and frequency shocking conditions

Hassan Elahi,Zubair Butt,Marco Eugnei,Paolo Gaudenzi,Asif Israr 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.9

Piezoelectric materials are widely used as smart structures in cubic reconnaissance satellites because of their sensing, actuating, and energy-harvesting abilities. In this study, an analytical model is developed in specific mechanical thermal shocking conditions. A special circuit and apparatus is designed for experimentation on the basis of the inverse piezoelectric effect. An equivalent circuit method is used to establish the relationship between the resistance and peak-to-peak voltage of lead zirconate titanate used as smart materials for cubic reconnaissance satellites. Various frequencies and resistance were applied in different mechanical thermal shocking conditions. Moreover, numerical simulations are conducted in various mechanical loading conditions to determine the accumulative effect. The model provides a novel mechanism to characterize the smart structures in cubic reconnaissance satellites. A rise in temperature increases peak-to-peak voltage; a rise in frequency decreases peak-to-peak voltage; and intensified resistance decreases peak-to-peak voltage. Based on experimentation and simulation, the optimum resistance is predicted for the various frequencies and temperatures. The various conditions may correspond to the different applications of smart structures for cubic reconnaissance satellites. The analytical calculations are in good agreement with experimental and numerical calculations.

Sustainable Utilization of Powdered Glass to Improve the Mechanical Behavior of Fat Clay

Hassan Mujtaba,Usama Khalid,Khalid Farooq,Mehboob Elahi,Ziaur Rehman,Hussain Mustafa Shahzad 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.12

Civil engineering infrastructure like roads, bridges, railway tracks, and building structures constructed on fat clay becomes suspicious due to adverse change in the behavior of such soil on interaction with water. To solve such problems especially in underdeveloped countries, application of industrial waste like glass is associated with technical, financial, and environmentalbenefits. Emphasis of current study is to determine the consequences of powdered glass (GC) on mechanical behavior of fat clay. A fat clayey sample was collected from location of Nandipur, and glass was taken from local glass market in powdered form. Samples were remolded at optimum moisture content and maximum dry unit weight by mixing GC up to 14%. Soil classification tests, modified compaction tests, unconfined compression tests, one-dimensional consolidation tests, California bearing ratio (CBR) tests, and scanning electron microscope were performed. With increasing GC, the consistency limits, compression characteristics, swell characteristics, and optimum moisture content decreased while maximum dry unit weight, yield stress, CBR, and unconfined compression strength increased. Influence of GC is also observed on microstructure of treated clay. After 12% GC, aforementioned geotechnical characteristics behave inversely for selected clay. The optimum GC-value for the tested clay is about 12%, however, this value may vary from clay to clay.

Experimental and numerical investigation of transversal damage in carbon fiber reinforced composites using X-FEM analysis

R. F. Swati,L. H. Wen,Hassan Elahi,A. A. Khan,S. Shad 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

Damage modelling along with crack behavior carbon fiber resin reinforced composites under tensile and three-point bending loading were simulated in this study for different variables and cases. Extensive experimentation was performed for carbon fiber composites by grouping them into different categories of layup, orientations and boundary conditions accordingly. The specimen dimensions and the loading conditions were evaluated in the mentioned categories for the transversal damage as a primary objective of the study. The composite models for single layer and multilayer were modelled in extended finite element method (XFEM) module in ABAQUS software, and interaction subroutines were included for the mentioned models and experimental behavior and response were studied. The damage progress was investigated and then the criteria of stress-strain as well as stress distributions/intensity factor in the fiber and matrix were the outputs. The purpose of the study was to validate the numerical and simulation outputs with experimental results for XFEM as a framework for the crack initiation, propagation along an arbitrary, mesh-independent, solution-dependent path, which is being widely used. The key parameters and critical aspects of convergence of the results, while carrying out damage and fracture analysis when using numerical simulation in comparison with the experimentation setup, required precise and accurate understanding towards modelling the above-mentioned cases. The study offers novel methodology and pre-development of framework for crack modelling from single to multi-crack for carbon fibers. The study started with the results from previous studies of both transversal cracks and delamination followed by the study of fracture in the material. Different specimens were studied and tested, and the results were in close convergence between experimental and numerical data for multiple cases.

Characterizing Barium Titanate Piezoelectric Material Using the Finite Element Method

Butt, Zubair,Rahman, Shafiq Ur,Pasha, Riffat Asim,Mehmood, Shahid,Abbas, Saqlain,Elahi, Hassan The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.3

The aim of the current research was to develop and present an effective methodology for simulating and analyzing the electrical and structural properties of piezoelectric material. The finite element method has been used to make precise numerical models when dielectric, piezoelectric and mechanical properties are known. The static and dynamic responses of circular ring-shaped barium titanate piezoelectric material have been investigated using the commercially available finite element software ABAQUS/CAE. To gain insight into the crystal morphology and to evaluate the purity of the material, a microscopic study was conducted using a scanning electron microscope and energy dispersive x-ray analysis. It is found that the maximum electrical potential of 6.43 V is obtained at a resonance frequency of 35 Hz by increasing the vibrating load. The results were then compared with the experimentally predicted data and the results agreed with each other.

Generation of electrical energy using lead zirconate titanate (PZT-5A) piezoelectric material: Analytical, numerical and experimental verifications

Zubair Butt,Riffat Asim Pasha,Faisal Qayyum,Zeeshan Anjum,Nasir Ahmad,Hassan Elahi 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.8

Energy harvesting is the process of attaining energy from the external sources and transforming it into usable electrical energy. An analytical model of piezoelectric energy harvester has been developed to determine the output voltage across an electrical circuit when it is forced to undergo a base excitation. This model gives an easy approach to design and investigate the behavior of piezoelectric material. Numerical simulations have been carried out to determine the effect of frequency and loading on a Lead zirconate titanate (PZT-5A) piezoelectric material. It has been observed that the output voltage from the harvester increases when loading increases whereas its resonance frequency decreases. The analytical results were found to be in good agreement with the experimental and numerical simulation results.

Characterizing Barium Titanate Piezoelectric Material Using the Finite Element Method

Zubair Butt,Shafiq Ur Rahman,Riffat Asim Pasha,Shahid Mehmood,Saqlain Abbas,Hassan Elahi 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.3

The aim of the current research was to develop and present an effective methodology for simulating and analyzingthe electrical and structural properties of piezoelectric material. The finite element method has been used to makeprecise numerical models when dielectric, piezoelectric and mechanical properties are known. The static anddynamic responses of circular ring-shaped barium titanate piezoelectric material have been investigated using thecommercially available finite element software ABAQUS/CAE. To gain insight into the crystal morphology and toevaluate the purity of the material, a microscopic study was conducted using a scanning electron microscope andenergy dispersive x-ray analysis. It is found that the maximum electrical potential of 6.43 V is obtained at a resonancefrequency of 35 Hz by increasing the vibrating load. The results were then compared with the experimentally predicteddata and the results agreed with each other.