Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
Volume:14 Issue: 2, May 2022

The exhaust manifolds are subjected to higher loads than before, due to the increasing power output, fuel consumption and exhaust gas emission. Thus, simulation and analysis of fatigue cracks is essential. The effect of residual stress on the thermal stress and low cycle fatigue (LCF) life of exhaust manifolds using strain life methods was investigated. For this purpose, Solidworks software was used to model the exhaust manifolds. Then the thermo-mechanical analysis was carried out to determine the temperature and stress distribution in ANSYS software.  Finally, the fatigue life prediction that considers residual stress effect was done. The simulated results proved that the thermal stresses and number of cycles to failure have the most critical values at the confluence region of the exhaust manifolds. The LCF results showed that the number of failure cycles for coated exhaust manifold is about 89% higher than the results obtained from the uncoated exhaust manifolds. Evaluating the residual stress, the TBC improves the number of failure cycles approximately 52% in comparison the uncoated exhaust manifold. The results of FEA proved a very good agreement between numerical simulation results and LCF analysis results, performed in references.

Tooth extract is a chronic disease affecting a large number of people, especially children. Due to the high rate of tooth decay and the effect of nutrition and obesity on dental caries, this paper aims to investigate the relationship between body mass index (BMI) and dental caries (dmft) in children. This descriptive-analytical study was performed on a sample of 232 children age 6 to 9 years referred to Khorramabad Dental School in the academic year 2020-2021. The height, weight and BMI were measured for all children and their dmft score was determined based on the criteria of standards defined by the World Health Organization (WHO) and the data were analyzed using STATA 14 software. The obtained results showed that the mean age of students was 7.351±0.07 years, their BMI was 15.39 ± 2.81 and their dmft was 5.51 ± 2.8 are underweight, 26.29% are normal weight, 12.5% ​​are overweight and 6% are fat. Moreover, in this research molecular dynamics (MDs) simulation was used to predict the physical and mechanical properties of lithium disilicate as a restorative material. According to the experimental results, the mean dmft index in Khorramabad students is high and programs should be considered to control dental caries and reduce them. Regarding the relationship between dmft and BMI, contradictory results were obtained that due to the multifactorial nature of caries and obesity, the relationship between the two is complex and needs further investigation. The average density value of the simulated model of lithium disilicate is 2.551 at 300 K and 2.479 gr/cm3 at 450 K, which is very close to the real value of 2.6 ± 0.3 gr/cm3. The obtained results from the MDs showed that it is in good agreement with the experimental observation.

To investigate the influence of aluminum anodization voltage on the barrier layer thickness of porous anodic alumina (PAA) and its electric resistance used in different technologies such as strain-sensing technology, samples in different voltages and variety condition of mild and hard anodization were fabricated. In different researches, different anodic alumina thicknesses have been tested and their effect on protection against humidity is studied by monitoring sensor resistance. Measurement of electrical resistant of barrier layer during the voltage changing shows that there is a transition region in which electric resistance of samples is located between hard and mild anodized region. The SEM investigation reveals that the barrier layer thickness is linearly proportional to the anodization voltage. But the barrier layer resistance in hard anodization is lower than that one in mild anodization. The observed paradox can be related to higher ionic mobility of ions in barrier layer which is formed in hard anodization.

Titanium Alloys due to appropriate physical and mechanical properties, have broad industrial applications. Electro discharge machining (EDM) is a widely accepted non-traditional material removal process used to manufacture titanium alloys components with intricate shapes and profiles. Using powder as additive for increasing performance of EDM process has been recently investigated. This process is called powder mixed EDM (PMEDM), which is a complex machining process and is governed by a number of machining parameters. The objective of present research is to realize the potential of Al2O3 powder as additive in enhancing performance of PMEDM on Ti6Al4V. Full factorial technique has been adopted to plan and analyze the experimental results. Pulse on time, pulse off time, current and powder are taken as machining parameters. Material removal rates (MRR), tool wear rate (TWR) and surface roughness (SR) are taken as response parameters. The results of variance analysis of the results show that the current, pulse on time, pulse off time, and powder have, respectively, the greatest effects on the results and the surfaces of samples is better with powder than without powder.

This work aims to develop models to investigate the effects of flank wear on cutting forces during the turning of ck45 steel using carbide tools. Therefore, various turning experiments were performed with different cutting conditions. Flank wear and cutting forces were recorded at different stages of each experiment. The data obtained from the experiments showed that the tangential component of the cutting force was not significantly correlated with the tool flank wear. Instead, there was a good correlation between the axial and radial components of the cutting forces against flank wear. Since the cutting forces depend on both the cutting conditions and the tool flank wear, different cutting forces and cutting condition ratios were used to find the cutting force models that are more sensitive to tool wear. These ratios were used to develop artificial neural network models. The statistical results showed that the tool wear obtained from the artificial neural network models was very close to the results obtained from the experiments. In addition, the accuracy of the models including the axial component of cutting force was higher than in other models.

Drug release in the body, mainly by digestive (tablets, capsules, and syrups) and non-digestive (injections, eye drops, and creams) are known as conventional technique. In most of these methods, the drug travels through the body during exposure to the acidic environment of the stomach, passing through the tight connections of cells in the intestinal wall. This attitude is based on the fact that a sufficient concentration of the drug enters the bloodstream. The process of targeted drug delivery maintains the level of an appropriate drug concentrations for a long time and reduces many of the usual therapeutic limitations such as the number of doses used. In this research, the use of natural biopolymers in the engineering and medical engineering industries and the use of electro spraying for core-shell have been investigated. Also, the side effects of simple drug release in the systemic distribution are unclear. Each targeted delivery system includes a target drug, carrier, and ligand, in which the distribution, metabolism, and cellular uptake of the drug are determined by the physicochemical characteristics and biological behavior of the carrier and ligand. Therefore, proper carrier and ligand design increases drug efficacy in patient tissues and reduces drug toxicity in other healthy tissues. Many new techniques such as electrospray using natural polymers can use for treatment of those disease with sufficient time of drug release using an appropriate drug.