The ring inside the one-way valve has an important role in the reciprocating compressor. In this article, two different materials for rings were considered; stainless steel with the material number 1.5022 and sign 38si6, and carbon-peek composite. These two rings were prepared in valves with identical conditions in design and manufacturing and were used in reciprocating compressors with the same applications. The results of this experiment showed that the life of the valve with a steel ring was 145 days, while the valve with a carbon-peek ring was intact after 210 days. The most important reason for early failure in the steel ring is an inappropriate distribution of forces due to the springs below the ring. Another common cause of failure in these valves is the stresses on walls in the location of springs. Therefore, in this paper, the stresses in the chamber of springs, which are critical points in the design and construction of the valves, are also discussed. By using robust business codes like Abaqus software, the design and analysis stages of the valve are carried out in quasi-static conditions. The stresses and tensions on the chamber of spring and the ring are much stronger in the steel ring than the carbon-peek composite ring. The results obtained from numerical simulations are consistent with experimental observations. In addition, accurate thickness for the ring was determined by use of flow relations.
 

Efforts to reduce the ballistic effects and achieve the good results have always been important. In this article, perforated targets were used in order to reduce the penetration depth of projectile. The use of these targets in the case of high-speed projectiles reduces the number of parameters, such as penetration depth, cost of target products, and target area density. The goal of this paper was to present a new and complete analytical model for projectile penetration in ceramic/metal semi-infinite perforated targets, based on the Fellows analytical model, one of the most important models for penetration. First, the Fellows model was modified for ceramic/metal semi-infinite none-perforated targets. This modified model, while perfectly improving the results of the penetration depth at low speeds and had a better fit with experimental results at high speeds. In the new analytical model, 7 different states were considered for the projectile to impact the perforated target. In each of these states, the angle of oblique and the speed of the projectile after reaching the metal varied with respect to the ceramic thickness and the speed of the projectile's impact. Regarding the oblique impact on the metal, corrected relations were rewritten for new conditions. Finally, the depth of penetration was achieved according to the target conditions. The numerical simulation in Abaqus software was used to compare the results. The results of the new analytical model has good agreement with numerical simulation.

Design and safety of natural gas tanks Due to its high use in cars, it is of great importance. Therefore, in this paper, the empirical, numerical and optimization of these reservoirs is investigated. Experimental section designed and manufactured two metal and composite tanks that have been tested for internal pressure and their strength has been determined. Modeling of these tanks has been done in the numerical section with the help of Abaqus software 6.14. In addition to validating the results with experimental data, numerical simulation has been developed. Using the results of the development of numerical simulation and experimental design software, optimization of parameters and their relationship with pressure tolerance in these tanks have been investigated. The numerical and experimental results are in good agreement. Lightweight composite tanks are more resistant to internal pressures, which resulted in a 30% reduction in the weight of composite tanks and a 20% reduction in deformation under operating pressure.

In impact mechanics, layered targets are important due to their high resistance to projectiles penetration. This paper deals with the analytical and numerical analysis of the penetration of tantalum projectiles on semi-infinite ceramic-metal layered targets. In the analytical study, a new modified analytical model based on the analytical model of Fellows is presented. The modifications made to the Fellows analytical model include the changes of velocity of the projectile and ceramic, the angle and timing of the formation of the ceramic cone, the erosion of ceramic, projectile and backing. Each of these modifications alone reduces or increases the depth of penetration, and all of these modifications together improve the depth of penetration. Numerical analysis is done using Abaqus software. The behavior of projectile, ceramic, and aluminum is modeled on the actual behavior of the materials and the deformation. The projectile and backing behavior is modeled with the Johnson-Cook equations and the ceramic behavior with the Drucker-Prager plasticity equation and the state equation of Mie-Gruneisen. The results of the new correction analytical model and numerical simulation are compared with the results of other authors and experimental data. The results show very good agreement. The new modified analytical model, by removing the Fellows model defects, provides a more accurate prediction of the depth of projectile penetration in the ceramic-metal layered targets. So, the weakness of this model, which is related to the unpredictability of penetration depth at low speeds, has been remedied.