Faisal Qayyum - Academia.edu (original) (raw)

Papers by Faisal Qayyum

Crystals, 2022

This work investigates a ferrite matrix with multiple non-metallic inclusions to evaluate their i... more This work investigates a ferrite matrix with multiple non-metallic inclusions to evaluate their influence on the global and local deformation and damage behavior of modified 16MnCrS5 steel. For this purpose, appropriate specimens are prepared and polished. The EBSD technique is used to record local phase and orientation data, then analyze and identify the size and type of inclusions present in the material. The EBSD data are then used to run full phase crystal plasticity simulations using DAMASK-calibrated material model parameters. The qualitative and quantitative analysis of these full phase simulations provides a detailed insight into how the distribution of non-metallic inclusions within the ferrite matrix affects the local stress, strain, and damage behavior. In situ tensile tests are carried out on specially prepared miniature dog-bone-shaped notched specimens in ZEISS Gemini 450 scanning electron microscope with a Kammrath and Weiss tensile test stage. By adopting an optimize...

The Arabian Journal for Science and Engineering, Feb 3, 2015

Compact tension (CT) specimen is used to investigate the behavior of fatigue crack growth rate (F... more Compact tension (CT) specimen is used to investigate the behavior of fatigue crack growth rate (FCGR) of preheat-treated tungsten inert gas (TIG) welded aluminum alloy (AA2219-T87) on MTS-810. Filler metal used for weld is AA2319. ASTM E399 standard provides a method to convert crack mouth opening displacement (CMOD) data to crack length in CT specimens. Calibration tests are performed to obtain the plots of CMOD versus load and CMOD versus crack ratio (a/W) for different crack lengths in the base metal and the welded metal. Cracks lengths are obtained optically and calculated from CMOD as per ASTM E399. Numerical simulation is used to relate the crack length with CMOD in base metal. Validity of the ASTM standard is verified with the results obtained. Paris curves are plotted and compared for both base metal and welded metal to study the effects of welding on FCGR. It is shown that calculation of crack length through CMOD measurements is not reliable in the case of welded materials. High amount of crack closure exists in welded material, which induces large errors in calculated crack length. The microstructure evolves as a result of the TIG welding. The center of the weld nugget zone consists of dendritic structure followed by recrystallized equiaxed small-sized grains in the heat-affected zone. Grains have elongated structure in the base metal. Due to varying phase conditions and concentration of strengthening particles, a high contrast under optical microscope is clearly observed in different zones of weldment.

Nuclear Science and Techniques, 2019

The reactivity of a nuclear reactor is the most important safety and operating parameter. Due to ... more The reactivity of a nuclear reactor is the most important safety and operating parameter. Due to short reactor period, the Light Water Reactor (LWR) designs require the compensations of rapid unfavorable reactivity increases. The increase in fuel or moderator temperature leads to compensate the reactivity jumps as inherent safety characteristics. The safe and reliable reactor operation requires the accurate assessment of these reactivity changes. This paper highlights the improvements in the methodology to determine the feedback reactivity changes in IAEA MTR benchmark. This method incorporates the reactivity effects of fuel temperature in moderator regions and vice versa. For this purpose, a detailed 3D model of the IAEA 10 MW MTR benchmark reactor is developed employing OpenMC computer code. OpenMC is a probabilistic computer code for neutronic calculations. This work uses temperature-dependent JEFF 3.2 cross-sectional library. The model is validated against the reference results of eigenvalues for control rods (inserted and in fully withdrawn position), control rod reactivity worth, averaged thermal flux in the central flux trap, and power fraction for each fuel element at beginning of life. The validated model is applied to simulate the feedback reactivity coefficients against the conventional reference results. In order to improve the methodology, the effect of the moderator temperature and void on fuel is incorporated to obtain a more realistic value of the fuel temperature coefficient. Similarly, the moderator temperature coefficient and void coefficient are improved by incorporating the coupling effects of fuel temperature on moderator. This methodology can be applied to improve the LWR designs. Keywords OpenMC Á MTR benchmark Á Reactivity feedback coefficients Á Fuel temperature coefficient Á Moderator temperature coefficient Á Void coefficient of reactivity

IOP Conference Series: Materials Science and Engineering, 2016

Alumina ceramics having small grain size and high density yield good mechanical properties, which... more Alumina ceramics having small grain size and high density yield good mechanical properties, which are required in most mechanical applications. Two Step Sintering (TSS) is used to develop dense alumina ceramics. In this research work the effect of sintering temperatures on microstructure and density of the alumina specimens developed by using TSS has been investigated. It has been observed that TSS is more efficient in controlling grain growth and increasing the density as compared to One Step Sintering (OSS) of alumina. Scanning electron micrographs of sintered alumina specimens have been compared. It has been observed that TSS proves to be a better technique for increasing density and controlling grain growth of alumina ceramics than OSS. More relative density, hardness, fracture toughness and small grain size was achieved by using TSS over OSS technique.

Engineering Failure Analysis, 2016

Thermal fatigue is one of the key reasons of material failure in components which are exposed to ... more Thermal fatigue is one of the key reasons of material failure in components which are exposed to high temperature cycles. Prediction of crack initiation site and crack propagation speed during thermal cycling helps us predict the life of a component in service. In this research numerical simulation of crack propagation due to thermal cycling on a circular disc has been carried out. The thermal profiles used in the simulation are taken from actual thermal fatigue experiments. The effect of the length of cracks and interaction between adjacent cracks has been investigated. 50 sets of numerical simulation models with different crack numbers and crack lengths have been simulated. The variation in Stress Intensity Factor (SIF), hoop stress and Crack Mouth Opening Displacement (CMOD) has been plotted as a function of primary/secondary crack lengths and number of cracks. Envelopes of possible crack growth have been identified and correspond well to the experimental observations. Results show a significant drop in hoop stress, SIF and CMOD with increase in number of cracks, thus limiting the number of cracks possible in a thermal fatigue crack network.

Acta Metallurgica Sinica (English Letters), 2013

Single-edged notched tension (SENT) specimen is used to study the fatigue crack growth rate (FCGR... more Single-edged notched tension (SENT) specimen is used to study the fatigue crack growth rate (FCGR) behavior of AISI 50100 steel using MTS 810. Calibration tests are run to get plots of crack mouth opening displacement (CMOD) vs. load and CMOD vs. crack length-to-width ratio with the known crack lengths. Numerical simulation is also done to try to establish a relation between crack length and CMOD. FCGR of welded and un-welded specimens are plotted against stress intensity factor range to show the effect of welding on fatigue crack growth rate of AISI 50100 steel. The experimentally obtained CMOD values are compared with values obtained by numerical simulation using ABAQUS/Standard TM software package. Results show that numerical values are in good agreement with experimental data for small crack lengths and lower values of applied load.

Journal of Composites Science, 2021

This research uses EBSD data of two thermo-mechanically processed medium carbon (C45EC) steel sam... more This research uses EBSD data of two thermo-mechanically processed medium carbon (C45EC) steel samples to simulate micromechanical deformation and damage behavior. Two samples with 83% and 97% spheroidization degrees are subjected to virtual monotonic quasi-static tensile loading. The ferrite phase is assigned already reported elastic and plastic parameters, while the cementite particles are assigned elastic properties. A phenomenological constitutive material model with critical plastic strain-based ductile damage criterion is implemented in the DAMASK framework for the ferrite matrix. At the global level, the calibrated material model response matches well with experimental results, with up to ~97% accuracy. The simulation results provide essential insight into damage initiation and propagation based on the stress and strain localization due to cementite particle size, distribution, and ferrite grain orientations. In general, it is observed that the ferrite–cementite interface is p...

steel research international

Crystals

The mechanical behavior of newly developed composite materials is dependent on several underlying... more The mechanical behavior of newly developed composite materials is dependent on several underlying microstructural phenomena. In this research, a periodic 2D geometry of cast X8CrMnNi16-6-6 steel and 10% zirconia composite is virtually constructed by adopting microstructural attributes from literature. A physics-based crystal plasticity model with ductile damage criterion is used for defining the austenitic steel matrix. The zirconia particles are assigned elastic material model with brittle damage criterion. Monotonic quasi-static tensile load is applied up to 17% of total strain. The simulation results are analyzed to extract the global and local deformation, transformation, and damage behavior of the material. The comprehensively constructed simulation model yields the interdependence of the underlaying microstructural deformation phenomena. The local results are further analyzed based on the interlocked and free regions to establish the influence of zirconia particles on micro-me...

Crystals

Crystal plasticity simulations help to understand the local deformation behavior of multi-phase m... more Crystal plasticity simulations help to understand the local deformation behavior of multi-phase materials based on the microstructural attributes. The results of such simulations are mainly dependent on the Representative Volume Element (RVE) size and composition. The effect of RVE thickness on the changing global and local stress and strain is analyzed in this work for a test case of dual-phase steels in order to identify the minimal RVE thickness for obtaining consistent results. 100×100×100 voxel representative volume elements are constructed by varying grain size and random orientation distribution in DREAM-3D. The constructed RVEs are sliced in depth up to 1, 5, 10, 15, 20, 25, 30, 40, and 50 layers to construct different geometries with increasing thickness. Crystal plasticity model parameters for ferrite and martensite are taken from already published data and assigned to respective phases. Although the global stress/strain behavior of different RVEs is similar (<5% diverg...

Materials

In this research, the effect of 2D and 3D Representative Volume Element (RVE) on the ductile dama... more In this research, the effect of 2D and 3D Representative Volume Element (RVE) on the ductile damage behavior in single-phase (only ferrite) and dual-phase (ferrite and martensite) steels is analyzed. Physical and fitting parameters of the constitutive model for bcc-ferrite and bcc-martensite phases are adapted from the already published work. Crystal plasticity (CP) based numerical simulations without damage consideration are run and, later, ductile damage criteria for the ferrite phase is defined for all cases. The results of the non-damage (-nD-) and damage (-D-) simulations are compared to analyze the global and local differences of evolving stresses and strains. It is observed that for the same model parameters defined in all cases, damage initiation occurs at the overall higher global strain in the case of 3D compared to 2D. Based on statistical data analysis, a systematic comparison of local results is carried out to conclude that the 3D RVEs provide better quantitative and qu...

2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)

The influence of microstructural attributes of crystalline material on its overall mechanical pro... more The influence of microstructural attributes of crystalline material on its overall mechanical properties is of vital importance to get the desired plasticity of a component. Varying grain morphology and distribution of the multi-phase steels can pose plastic flow challenges during cold forming. The spheroidized medium carbon steels obtained by reforming the lamellar structured hard cementite particle networks present in alternating layers with soft ferrite phase in pearlite have remarkable microstructure with an overall better combination of ductility and strength. The spherical shaped cementite particles in spheroidized mild steel are responsible for heterogeneous material response at the local level during deformation due to their hard and strong nature. It eventually alters the overall mechanical behavior due to their size and distribution in the soft ferrite matrix. It is, therefore, necessary to precisely predict the mechanical response of the material by numerical simulations using microstructural models and crystal plasticity code. In this research study, Voronoi Tessellation based customized algorithms in Dream.3D are used to make microstructural models of spheroidized medium carbon steel. Crystal plasticity based constitutive mathematical material model is evaluated on continuum mechanics principles using DAMASK code. Representative Volume Elements (RVEs) with cementite particles spread 50% on the ferrite grain boundaries are first ensured to be grid-independent. RVEs of three cases with varying ferrite grain size, i.e., small, large, and bimodal, are simulated under tensile loading up to 30% of global strain. Local stress and strain maps of the RVEs are critically analyzed. The changing effect of the cementite grain size and distribution within the ductile ferrite phase on local material behavior is observed. Stress localization is observed on the bases of the distribution of cementite phase particles and quantitatively presented. The information can be used to better design the thermo-mechanical processing of the mild steel sheets and rods to get a better mechanical response during plastic deformation in cold forming processes such as in the automotive industry.

steel research international

Applied Sciences

Physics-based and phenomenological crystal plasticity numerical simulations provide an opportunit... more Physics-based and phenomenological crystal plasticity numerical simulations provide an opportunity to develop microstructurally informed models for multi-phase material. The Düsseldorf Advanced Material Simulation Kit (DAMASK) has been developed as a flexible tool for modeling and studying the several deformation mechanisms of such materials at the microscopic and macroscopic scales. In the recent past, several methodologies and techniques were developed for obtaining or constructing microstructural details and calibrating the physics-based model parameters for single-phase and multi-phase materials. Combining and standardizing the devised methods with an appropriate database can help establish a virtual laboratory to analyze the effect of microstructural attributes on the mechanical behavior of multi-phase materials. This article deals with the comprehensive background of the developed techniques and methods for the multi-phase materials class by the current research group. The com...

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications

In this research, percentages of nickel as austenizer and chromium as ferritizer, in the molten m... more In this research, percentages of nickel as austenizer and chromium as ferritizer, in the molten metal pool of SS304L weldments are varied to analyze the effect on the produced delta ferrites morphology and volume. The resulting localized precipitation of delta ferrite and its effect on the fatigue crack propagation rate of the material are examined in this work. The estimation of localized delta ferrite number for a particular weld zone is assessed through the development of a MATLAB code for image processing. It is observed that a reduction in the percentage of nickel in filler alloy yields randomly scattered granular ferrites in the fusion zone and equiaxed grain growing in the heat-affected zone with the development of blocky ferrites on the grain boundaries, whereas increased percentage of chromium in the filler causes the precipitation of dendritic clusters and vermicular ferrites in fusion zone and heat-affected zone of weldments, respectively. The effect of ferrite numbers an...

Integrated Ferroelectrics

Abstract From the last few decades, the piezoelectric materials are playing a vital role in the f... more Abstract From the last few decades, the piezoelectric materials are playing a vital role in the field of energy harvesting because of their capability to convert mechanical energy from the surroundings into useful electrical energy. In this research, the performance of the piezoelectric energy harvester (PEH) in cantilever configuration with varying length and width of the patch as compared to the beam was analyzed. Moreover, the induced voltage and power harvested by the designed PEH are analyzed for the various configurations of piezoelectric patch (PZTp). The effect of length and width of the PZTp and beam is predicted for the energy harvesting phenomenon. The effect of different piezoelectric materials [i.e. Lead zirconate titanate (PZT-5A) and Barium titanate (BaTiO3)] bonded to different non-piezoelectric materials (i.e. Aluminum (Al) and fiberglass) is studied analytically. An analytical model is developed for three different cases to analyze the effect of varying patch length while keeping the length of the beam variable. Finite Element Models to study energy harvesting and modes of vibration for all three cases were developed. The results of the analytical model and numerical model are compared with experimental investigations and are found to agree with a maximum of 22% error. For the designed harvesters, the maximum power output is obtained for the test case in which PZT-5A patch of smaller length is bonded with Al patch of larger length. The analytical, numerical and experimental results depict a similar trend.

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications

The interaction of mechanical components experiencing relative movements and cyclic loads in a co... more The interaction of mechanical components experiencing relative movements and cyclic loads in a corrosive environment is known as fretting corrosion or tribocorrosion. In the current work, the mechanism of crack initiation and propagation in dovetail slots of Ti6Al4V samples (in contact with carbide rods) under fretting corrosion conditions was investigated. A newly developed test rig installed on a universal testing machine was used to conduct tests at 20 Hz frequency under 5 and 7.5 kN fretting loads. Tests were conducted at room temperature in 3.5% NaCl and phosphate-buffered saline solutions. Crack propagation in all samples was examined by a metallurgical microscope, and the detailed analysis of fractured samples was carried out by a scanning electron microscope. In comparison to dry conditions, early crack initiation and faster crack propagation were observed in salt and physiological solution environments. Colored spots and large amounts of chlorine, sodium, and oxygen were fo...

Crystals, 2022

The Arabian Journal for Science and Engineering, Feb 3, 2015

Nuclear Science and Techniques, 2019

IOP Conference Series: Materials Science and Engineering, 2016

Engineering Failure Analysis, 2016

Acta Metallurgica Sinica (English Letters), 2013

Journal of Composites Science, 2021

steel research international

Crystals

Materials

2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)

steel research international

Applied Sciences

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications

Integrated Ferroelectrics

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications