OPTIMIZATION OF MECHANICAL BEHAVIORS OF BIO PARTICULATES FILLED COIR-POLYESTER COMPOSITES USING SIMULATED ANNEALING

ABSTRACT The mechanical behaviors of Coir-Polyester composites are greatly improved by the impregnation of bio particulates. The present investigation is focused on the evaluation and optimization of mechanical behaviors of CoirPolyester composites filled with bio particulates such as red mud and termite mound soil. The composite fabrications were planned as per Design of Experiments with fabrication parameters like fiber length (mm) and particulate content (%). The tensile, flexural and impact strength of fabricated composites were evaluated as per ASTM standards. The effect of fiber length and particulate content on the mechanical behaviors of Coir-Polyester composites was studied using ANOVA and Response Surface plots. The nonlinear regression models were developed for the prediction of mechanical behaviors over the specified range of conditions. The fabrication parameters for the optimum value of mechanical behaviors were determined using the single solution metaheuristic algorithm called Simulated Annealing

Fatigue lives data

The fatigue lives data corresponding to Figures 8, 11, and 12 are provided in an excel file. The reader can find the data stored in three separate sheets within the excel file attached

Modeling Fatigue Behavior of Additively Manufactured Ni-Based Superalloys via Crystal Plasticity

Additive manufacturing (AM) introduces high variability in the microstructure and defect distributions, compared with conventional processing techniques, which introduces greater uncertainty in the resulting fatigue performance of manufactured parts. As a result, qualification of AM parts poses as a problem in continued adoption of these materials in safety-critical components for the aerospace industry. Hence, there is a need to develop precise and accurate, physics-based predictive models to quantify the fatigue performance, as a means to accelerate the qualification of AM parts. The fatigue performance is a critical requirement in the safe-life design philosophy used in the aerospace industry. Fatigue failure is governed by the loading conditions and the attributes of the material microstructure, namely, grain size distribution, texture, and defects. In this work, the crystal plasticity finite element (CPFE) method is employed to model the microstructure-based material response of an additively manufactured Ni-based superalloy, Inconel 718 (IN718). Using CPFE and associated experiments, methodologies were developed to assess multiple aspects of the fatigue behavior of IN718 using four studies. In the first study, a CPFE framework is developed to estimate the critical characteristics of porosity, namely the pore size and proximity that would cause a significant debit in the fatigue life. The second study is performed to evaluate multiple metrics based on plastic strain and local stress in their ability to predict both the modes of failure as seen in fractography experiments and estimate the scatter in fatigue life due to microstructural variability as obtained from fatigue testing. In the third study, a systematic analysis was performed to investigate the role of the simulation volume and the microstructural constraints on the fatigue life predictions to provide informed guidelines for simulation volume selection that is both computationally tractable and results in consistent scatter predictions. In the fourth study, validation of the CPFE results with the experiments were performed to build confidence in the model predictions. To this end, 3D realistic microstructures representative of the test specimen were created based on the multi-modal experimental data obtained from high-energy diffraction experiments and electron backscatter diffraction microscopy. Following this, the location of failure is predicted using the model, which resulted in an unambiguous one to one correlation with the experiment. In summary, the development of microstructure-sensitive predictive methods for fatigue assessment presents a tangible step towards the adoption of model-based approaches that can be used to compliment and reduce the overall number of physical tests necessary to qualify a material for use in application

Assessment of Efficacy and Safety Profile of Platelet Rich Plasma (PRP) Therapy with Dermaroller in the Treatment of Female Pattern Hair Loss

INTRODUCTION: Female pattern hair loss is the most common type of hair loss affecting women. Prevalence of FPHL is not well known as there is no universally accepted criteria for the disease. FPHL presents with hair thinning with 3 different patterns- Ludwig/Sinclair, Olsen & Hamilton. The visible thinning in FPHL results from follicular miniaturization. AIM OF THE STUDY: To find an effective alternative treatment modality for patients with female pattern hair loss of childbearing age. OBJECTIVE: To assess the efficacy and safety of Platelet Rich Plasma (PRP) therapy with Derma roller in the treatment of Female Pattern Hair Loss (FPHL). METHODOLOGY: In this study, 40 patients diagnosed as female pattern hair loss attending Dermatology outpatient department, who fulfilled the inclusion criteria were included. The patients were explained about the procedure, post-operative follow up and possible adverse effects. Four sittings of PRP with Derma roller was done at 1-month interval. Photos taken and grade improvement was noted. Final grading and images were taken at 2 months post treatment. RESULTS: About 87% of patients had improvement in the grade of hair loss after 6 months with better improvement seen after 3 sessions of treatment. The mean quality of life of the patients improved from 11 to 8 i.e.; from very large effect on patient’s life to moderate effect on patient’s life after 6 months. CONCLUSION: In this study, majority of the patients showed hair re-growth with decrease in hair fall and few patients showed decrease in hair fall despite having no improvement in hair loss. Majority of the patients did not experience any adverse effect. Thus, platelet rich plasma therapy with derma roller can be considered as an option in the treatment of female pattern hair loss with a good safety profile

Fatigue lives data

The fatigue lives data corresponding to Figures 8, 11, and 12 are provided in an excel file. The reader can find the data stored in three separate sheets within the excel file attached

Continuous Control Set-Model Prediktiv styrning av synkronmotor med permanent magnet

The thesis provides design methods for developing Continuous Control SetModel Predictive Control and Linear Quadratic Regulator for Interior mounted Permanent Magnet Synchronous Motor drive. The software for these controllers are implemented in the prototype motor at China Euro Vehicle Technology (CEVT) to estimate the computation time. The performance of these controllers are compared with Field Oriented Control based on Proportional Integral regulator. The comparative analysis for these controllers are performed in Model-in the Loop environment in Simulink developed by the company. It is a back-to-back set up where the test motor is driven by a load motor. The test motor is torque controlled while load motor is speed controlled. The motor is driven by a 2-level Voltage Source Inverter using Space Vector Modulation. The switching frequency of operation is 10 kHz for all controllers. Two variants of Model Predictive Control is discussed in this project. First is the reference tracking predictive control modelled as current controller for the drive. The absence of integral action is verified. Secondly, explicit integral action in Model Predictive Control and Linear Quadratic Regulator is introduced to handle the parameter mismatches. The three controllers, namely Proportional Regulator, integral states Model Predictive Control and Linear Quadratic Regulator where tested for their steady state current and torque tracking accuracy. The steady state ripples on current and torque is compared. The transient performance of the controllers are compared for torque reference changes and load disturbances. Sensitivity of the controllers to parameter mismatches is tested. Finally, ease of tuning these controllers are discussed. The computation time for the individual controllers are obtained by testing it in a microcontroller.Avhandlingen tillhandahåller designmetoder för utveckling av kontinuerlig kontrolluppsättning - modell för prediktiv kontroll och linjär kvadratisk regulator för interiörmonterad synkronmotordrift med permanent magnet. Mjukvaran för dessa styrenheter är implementerad i prototypmotorn hos China Euro Vehicle Technology (CEVT) för att uppskatta beräkningstiden. Dessa regulatorer jämförs i deras prestanda med Field Oriented Control baserad på proportionell integralregulator. Den jämförande analysen för dessa kontroller utförs i Modelin the Loop-miljön i Simulink utvecklad av företaget. Det är en back-to-backuppsättning där testmotorn drivs av en lastmotor. Testmotorn är vridmomentstyrd medan lastmotorn är varvtalsstyrd. Motorn drivs av en spänningskälla med två nivåer som använder Space Vector Modulation. Omkopplingsfrekvensen för driften är 10 kHz för alla regulatorer. Två varianter av Model Predictive Control diskuteras i detta projekt. Först är den prediktiva referensspårningskontrollen modellerad som aktuell styrenhet för frekvensomriktaren. Frånvaron av integrerad åtgärd verifieras. För det andra introduceras explicit integrerad åtgärd i Model Predictive Control och Linear Quadratic Regulator för att hantera parameterfelmatchningar. De tre styrenheterna, nämligen proportionell regulator, inbyggda tillstånd Model Predictive Control och Linear Quadratic Regulator testades med avseende på deras ström- och vridmomentspårningsnoggrannhet. Fortfarande rippel på ström och vridmoment jämförs. Regulatorernas transienta prestanda jämförs för vridmomentreferensändringar och laststörningar. Regulatorernas känslighet för parameterfel har testats. Slutligen diskuteras enkelheten att ställa in dessa kontroller. Beräkningstiden för de enskilda styrenheterna erhålls genom att testa den i en mikrokontroller

MODELING FATIGUE BEHAVIOR OF ADDITIVELY MANUFACTURED NI-BASED SUPERALLOYS VIA CRYSTAL PLASTICITY

Additive manufacturing (AM) introduces high variability in the microstructure and defect distributions, compared with conventional processing techniques, which introduces greater uncertainty in the resulting fatigue performance of manufactured parts. As a result, qualification of AM parts poses as a problem in continued adoption of these materials in safety-critical components for the aerospace industry. Hence, there is a need to develop precise and accurate, physics-based predictive models to quantify the fatigue performance, as a means to accelerate the qualification of AM parts. The fatigue performance is a critical requirement in the safe-life design philosophy used in the aerospace industry. Fatigue failure is governed by the loading conditions and the attributes of the material microstructure, namely, grain size distribution, texture, and defects. In this work, the crystal plasticity finite element (CPFE) method is employed to model the microstructure-based material response of an additively manufactured Ni-based superalloy, Inconel 718 (IN718). Using CPFE and associated experiments, methodologies were developed to assess multiple aspects of the fatigue behavior of IN718 using four studies. In the first study, a CPFE framework is developed to estimate the critical characteristics of porosity, namely the pore size and proximity that would cause a significant debit in the fatigue life. The second study is performed to evaluate multiple metrics based on plastic strain and local stress in their ability to predict both the modes of failure as seen in fractography experiments and estimate the scatter in fatigue life due to microstructural variability as obtained from fatigue testing. In the third study, a systematic analysis was performed to investigate the role of the simulation volume and the microstructural constraints on the fatigue life predictions to provide informed guidelines for simulation volume selection that is both computationally tractable and results in consistent scatter predictions. In the fourth study, validation of the CPFE results with the experiments were performed to build confidence in the model predictions. To this end, 3D realistic microstructures representative of the test specimen were created based on the multi-modal experimental data obtained from high-energy diffraction experiments and electron backscatter diffraction microscopy. Following this, the location of failure is predicted using the model, which resulted in an unambiguous one to one correlation with the experiment. In summary, the development of microstructure-sensitive predictive methods for fatigue assessment presents a tangible step towards the adoption of model-based approaches that can be used to compliment and reduce the overall number of physical tests necessary to qualify a material for use in application