Cylinder Of Material Research Articles

Research on the wear resistance of the material cylinder of an automatic injection molding machine during plastics processing

The article presents experimental studies of the pressure in the material cylinder of the D3328 automatic injection molding machine when processing various plastics, as well as experimental studies of wear along the length of the material cylinder of the DB3328 automatic injection molding machine after processing PS 68-30 fiberglass. Specially designed strain gauge pressure sensors were used. Signals from the sensors were output to an oscilloscope through the amplifying equipment and recorded on an oscillogram. The magnitude and distribution of pressure along the length of the material cylinder will significantly affect the amount of wear of both the screw and the cylinder. It was established that the pressure in the material cylinder of automatic injection molding machines is distributed unevenly along its length. The nature of the pressure distribution along the length of the material cylinder when processing various materials: during the injection period, the maximum pressure occurs in the melt zone with a subsequent sharp decrease in the middle zone and a slight increase in the loading zone. At the same time, the nature of the pressure change for all materials is similar at a diametrical gap between the screw and the cylinder δ=0.17 mm. With an increase in the gap δ to 0.74 mm, the nature of the pressure distribution in the injection zone changes only when processing fiberglass, which is due to the partial ingress of glass fibers into the gap between the screw and the cylinder. Its magnitude and nature of the distribution along the length for different materials are different and depend on the physical, mechanical and rheological characteristics of these materials, the design of the screw and the technological modes of processing. The maximum pressure occurs in the melt zone during the period of material injection into the mold for 0.4-0.5 s.

Dependence of wear intensity on the coating material of the hydraulic cylinder of the garbage truck’s sealing plate

The article is dedicated to the study of the influence of the coating material on the wear rate of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate. By means of a first-order planning of experiment with first-order interaction effects using the Box-Wilson method, an adequate dependence of the wear rate of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate on the coating material was determined. It is established that according to the Student’s criterion, among the studied factors of influence, the intensity of wear of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate is most affected by the iron content in the coating, the least – by the chromium content, and the nickel content affects only indirectly in interaction with the iron content. The response surfaces of the goal function – the intensity of wear of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate and their two-dimensional sections in the planes of the influence parameters are shown, which allow to clearly illustrate the specified dependence of this goal function on individual influence factors. The expediency of conducting further research to determine ways to further improve the wear resistance of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate is shown

Research on Motion Coupling Interior Ballistics of Cased Telescoped Ammunition Artillery

Abstract In this paper, the motion-coupled interior Ballistics of cased telescoped ammunition artillery is studied, and the physical process of the real interior ballistic process is analysed, on the basis of which, the gunpowder-gas energy conversion law at different stages and the combustion characteristics of the combustible guide cylinder are analysed, and the charge form function of the combustible guide cylinder material is established. Based on the classical interior ballistics theory, the motion-coupled interior ballistic theoretical model of cased telescoped ammunition artillery is established, taking into account the matching characteristics of the actual projectile and artillery movement. Combined with the energy conversion characteristics of the three phases, the set of internal ballistic control equations of cased telescoped ammunition artillery is numerically solved by the thermodynamic coupling and the fourth-order Lungkuta method, and the correctness of the theoretical model of the interior ballistics theory is verified by the firing test, and the results of the study can provide theoretical guidance for the related research and engineering application of the launching and controlling of cased telescoped ammunition artillery.

Comparison of Different Numerical Models for Solidification of Paraffin-Based PCMs and Evaluation of the Effect of Variable Mushy Zone Constant

The impact of the mushy zone parameter (Amushy) and the chosen numerical model during the solidification of a commercial paraffin-type phase change material (PCM) in a vertical cylinder under T-history conditions was examined through numerical simulations. The cooling process was modeled using three methods implemented in the CFD software ANSYS Fluent 2020 R2: the enthalpy–porosity method, the apparent heat capacity (AHC) method, and a new model proposed by the authors which incorporates heat capacity directly into ANSYS Fluent. To accurately define the boundary conditions, radiative heat transfer between surfaces was taken into account. Furthermore, the influence of the mushy zone parameter on the simulation accuracy and solidification rate was investigated, with the parameter being treated as a function of the liquid fraction. The results indicate that the proposed model aligns closely with experimental data regarding cooling temperature, offering better predictions compared to the other models. It was observed that temperature varies with time but not with position, suggesting that this model more effectively satisfies the lumped system condition—an essential characteristic of the T-history experiment—compared to the other methods. Additionally, the analysis showed that a higher mushy zone parameter enhances the accuracy of simulations and predicts a shorter solidification time; approximately 11% for the E-p and 7% for the AHC model. Using a variable mushy zone parameter based on the liquid fraction also produced similar results, resulting in an increased solidification rate.

Torsion and Extension of Functionally Graded Mooney–Rivlin Cylinders

We analytically study finite torsional and extensional deformations of rubberlike material circular cylinders with the two material moduli in the Mooney–Rivlin relation assumed to be continuous functions of the undeformed radius. It is shown that under null resultant axial load on the end faces the cylinder length increases upon twisting. Furthermore, when the two moduli are affine functions of the radius the inhomogeneity parameters can be found to have the maximum shear stress occur at a pre-determined interior point. Whereas the radial stress is finite at the center of a cross-section of a homogeneous material cylinder, it may have large values for an inhomogeneous material cylinder. The closed-form solutions provided herein for the two moduli having affine, power-law and exponential functions of the radius should benefit numerical analysts verify their algorithms and engineers design soft material robots for improving their performance under torsional loads.

CYLINDER AND PISTON: MATERIAL SELECTION IN THE DESIGN PHASE

The piston and cylinder constitute an inseparable pair, playing a crucial role in both the mechanical and hydraulic industries. They are frequently employed to convert linear motion into rotational motion in various types of engines and are especially valuable for heavy-duty applications. Material selection for these components is conducted during the product design phase. This study aimed to identify the optimal material for each type of product. To determine the best material, a ranking of materials was carried out using the CoCoSo (COmbined COmpromise SOlution) method, with scores for criteria calculated using the Entropy method. Nine materials for cylinder construction were evaluated, including S355JR, S275JR, S235JR, BS97007M20, R35, R45, IS1030GRADE, AISI304, and 60-40-18. Additionally, seven materials for piston construction were considered: 332-T5, A336, 242-T5, 333.0-F, A213.0 F, AISI308, and A319.0F. The Entropy-CoCoSo approach was employed to rank the materials for each case (cylinder material and piston material). The results indicated that AISI304 is the optimal material for cylinder manufacturing, while A336 is the best material for piston manufacturing. Furthermore, the study extensively examined the impact of different weighting methods (Entropy, WENSLO, CRITIC, ROC, RS, EW) and normalization techniques (sum, vector, max, max-min, peldschus, decimal) on CoCoSo method results using an innovative sensitivity analysis approach, analyzing the techniques according to their sensitivity levels.

Acoustic waves propagating through a fluid area containing randomly distributed coated cylinders

The research investigates acoustic wave propagation through a fluid region containing randomly arranged cylinders coated in identical materials, resulting in multiple scattering and the emergence of an effective wave. It examines the impact of the coating's viscoelasticity, cylinder material, and scatterer volume fraction on this wave. Additionally, it analyzes dispersion and attenuation as acoustic waves interact with the fluid region containing scatterers, particularly emphasizing normal incidence. This comprehensive study advances the understanding of wave scattering in random media, shedding light on this complex phenomenon. By delving into the complex interplay between wave behavior and material characteristics, the research provides valuable insights that can inform various acoustics and materials science applications, contributing to advancements in these fields.

Volumetric efficiency degradation prediction of axial piston pump based on friction and wear test

The axial piston pump (APP) is being developed towards higher pressure and higher rotational speeds to enhance operational power density. The piston-cylinder friction pair is a critical component of the APP. Due to its lack of self-compensation capability, the leakage of the piston-cylinder friction pair escalates rapidly under increasingly severe wear conditions. An innovative method for predicting the performance degradation and lifespan of APPs based on friction and wear tests has been proposed. This method can effectively predict the performance degradation trends of APPs under different operating conditions. The actual contact force on the piston pair (PP) during operation is determined through dynamic analysis. Friction and wear tests were conducted on 38CrMoAl piston and ZCuPb15Sn8 cylinder materials under various conditions using a testing apparatus. Utilizing friction and wear theory, the volumetric efficiency of APP under various operating conditions was derived as a function of operational time. The reliability of the theoretical analysis was validated through leakage tests on the APP. The results indicate that volumetric efficiency decreases exponentially with increasing working pressure at rated speed. This research provides theoretical guidance and an experimental foundation for the failure prediction of volumetric efficiency degradation in APP.

ACTION OF A SOLID BODY ON THE INNER SURFACE OF A THICK-WALLED BIMETAL CYLINDER

Purpose. The goal of the work is to obtain an exact solution to the problem of the stress-strain state of a long thick-walled bimetallic cylinder within the framework of the classical theory of elastic materials. Then, using the results obtained with this formulation, it is necessary to propose simpler engineering approaches and explore the possibilities of using asymptotic formulas for express analyzes at the design stage of such structural elements. Research methods. For the main body of the cylinder, the classical equations of the theory of elasticity in displacements are used. For the outer coating (sputtering), the shell theory equations are written based on the Kirchhoff-Love hypotheses. The complex integral Fourier transform and the Failon method are used to approximately find the original stresses and displacements. Asymptotic representations of cylindrical Bessel functions for large values of the argument and representations of improper integrals in the form of combinations of elementary and special tabulated functions are also used. Results. A mathematical model has been constructed to analyze the stress-strain state of a bimetallic cylinder with a thin outer layer of a material different from that of the inner layer. Various boundary conditions are recorded on the inner surface of the cylinder, describing the transmission from a rigid body of either specified forces or specified displacements. For all considered options, using the method of integral transformations, the results were obtained in the form of improper integrals, for the calculation of which a special method was used, aimed at calculating integrals with highly oscillating functions. Examples of specific graphs of changes in the components of the stress-strain state in the cylinder material are given. Depending on the conditions on the inner surface of the cylinder, simpler models are proposed to describe the main body, which are based, depending on the nature of the description of the interaction of the rigid body and the cylinder, on one equation of the theory of elasticity. With this approach, in some important cases it was possible to obtain improper inversion integrals using the asymptotic approach in closed form as a combination of elementary and special tabulated functions. Comparison with the exact approach allowed us to prove the possibility of using approximate models. Scientific novelty. A model of the behavior of a bimetallic cylinder as a body is constructed, the main layer of which is described by the equations of the theory of elasticity, and the theory of shells is used for the outer coating. Various methods of describing the transfer of forces and displacements from a rigid body to the inner surface of the cylinder are considered. The possibility of using the asymptotic approach to obtain relatively simple formulas for carrying out preliminary calculations at the design stage of such structural elements is shown.

Задача нелинейной теории упругости о растяжении и кручении составного цилиндра с предварительно напряжённым включением, содержащим винтовую дислокацию

The problem of large torsional and tension-compression deformations of a composite circular cylinder of incompressible Bartenev-Khazanovich material is considered. The cylinder contains a central circular cylindrical inclusion in which a concentrated screw dislocation is formed. It is pre-twisted and stretched (or compressed) along the axis and bonded to an unstressed external hollow cylinder. A single reference configuration is used when solving a problem for a composite body. This configuration is natural (unstressed) for the outer hollow cylinder and prestressed for the inner solid cylinder. The large deformation superposition theory is used to write the determining ratios of the material of the inner cylinder. The nonlinear theory of torsion of elastic cylinders containing a screw dislocation is used to solve the problem of the prestressed state of the internal inclusion. This theory is physically correct not for any models of isotropic elastic materials, but only for those for which the screw dislocation in the cylinder has a finite linear energy and creates a longitudinal force of finite value. The Bartenev-Khazanovich model belongs to this class. The problem for a composite cylinder is solved by a semi-inverse method. Using this method, it is reduced to nonlinear ordinary differential equations. The assumption of isotropy and incompressibility of the material makes it possible to find an exact solution to the problem.

Simulating the sealing performance of the double rubber cylinder assembly in an intelligent pipeline isolation tool

Intelligent pipeline isolation tools (IPITs) are widely used for pipeline maintenance and repair. Therefore, authors mainly study the sealing performance of double rubber cylinder IPIT. This study first analyzed the material and geometric properties of the rubber cylinders in an IPIT to establish a numerical finite element model of cylinder mechanical behavior. The influence of the cylinder hardness, camber angle, and short-side length on the sealing performance was subsequently investigated by systematically altering the established model according to the control variable method. Next, the response surface methodology was employed to evaluate the change in model sealing performance according to the coupled action of multiple rubber cylinder parameters and identify their optimal values.

Analysis of elastic stresses in rotating cylinders made of Titanium and Bronze materials

ABSTRACT This study analytically investigated elastic stress distribution in rotating cylinders made of Titanium and Bronze material. The Von Mises yield criterion was applied under the assumption of plane strain conditions. The modelling process considered that the disc material remains unaffected by temperature variations. The thermal stresses of a thin circular disc are being studied. The determined temperatures are close to the maximum and minimum temperatures at which the material can work. The numerical analysis is one, and the results are depicted as a whole with graphs. This study also examined the changes in the temperature distribution on the stress distribution. At the end of the study, it was determined that the stresses occurring in the titanium material cylinder were higher than the bronze disc, and the pressures were inversely proportional to the increase in the grading parameter in the cylinders. Additionally, the ANSYS finite element program was utilised for validation.

Scattering of shear horizontal waves by the piezomagnetic material cylinder embedded in an elastic medium

Scattering of shear horizontal waves by the piezomagnetic material cylinder embedded in an elastic medium

Advance optimum design of multi-layer compound cylinders

The purpose of this work is to find the optimum design for two-layer compound cylinders of the same material with an open end condition by using the elimination method. The optimization method depends on reducing the number of design variables with a simultaneous yield hypothesis for all layers of the compound cylinder. A combination of von Mises and Tresca criteria is used as a yield criterion, and the superposition principle is used to evaluate the equivalent stresses for each cylinder. By considering the working pressure and the internal diameter of the inner cylinder as the design parameters (constants during optimization) and the total thickness of the compound cylinder as the objective function, the optimization algorithm has been programmed in C# with a user-friendly graphical interface. The optimization results (outer diameter, interference diameter, and shrinkage pressure) are obtained for different working pressures and compared with the optimum design, which is based only on the Tresca criterion. The total mass of the compound cylinder can be reduced by up to 50% by using the von Mises–Tresca combination criterion. The optimized results are validated numerically by using finite element analysis in the ANSYS Workbench. The theoretical result and the FEA result agree with each other with errors of about 2%. The behavior of the optimized parameters for different working pressures is also observed and presented.

Biofilm volume and acidification within initial biofilms formed in situ on buccally and palatally exposed bracket material.

Acidification by bacterial biofilms at the bracket/tooth interface is one of the most common problems in fixed orthodontic treatments, which can lead to white spot lesions (WSL) and caries. As lingual brackets were shown to exhibit reduced WSL formation clinically, the aim of this in situ study was to compare initial intraoral biofilm formation and acidification on bracket-like specimens placed buccally and palatally in the upper jaw as apossible cause for this observation. Intraoral biofilm was collected from splints equipped with buccally and palatally exposed test specimens, which were worn by 12volunteers for atotal of 48 h. The test specimens consisted of standard bracket material cylinders on top of ahydroxyapatite disc to represent the bracket/tooth interface. They were analyzed for three-dimensional biofilm volume and live/dead distribution by fluorescence staining and confocal laser scanning microscopy as well as for acidification by fluorescence-based pH ratiometry. Similar general biofilm morphology with regard to volume and viability could be detected for buccally and palatally exposed specimens. For pH values, biofilms from both positions showed increased acidification at the bottom layer. Interestingly, the pH value at the top layers of the biofilms was slightly lower on palatally than on buccally exposed specimens, which may likely be due to anatomic conditions. Based on the results of this study, initial intraoral biofilm formation and acidification is almost similar on the bracket material/biomimetic tooth interface when placed buccally or palatally in the upper jaw. As lingual brackets were shown to exhibit reduced WSL formation clinically, future studies should investigate further factors like bracket geometry.

FUNCTIONAL ASSESSMENT OF WAVE PROPAGATION IN IMPERFECT CYLINDER MATERIALS

This work provides a theoretical framework to investigate the shear wave propagation properties within an Electrostrictive cylindrical layered structure. The structure is made up of a concentric, Functionally Assessed Electrostrictive Material (FAEM) cylindrical layer of limited width and an inadequately bonded Electrostrictive material cylinder. The FAEM layer has a constant functional gradient in the radial direction, and flaws at the interface are taken seriously, mirroring actual circumstances involving structural and electrical degradation. The fundamental electromechanical connected Bessel's equations are used to simplify field differential equations by mathematical modifications. Relationships for shear wave propagation under electrically short and open circumstances are established analytically. The acquired findings are verified against predefined standards and a particular issue instance. The impact of variables on the phase velocity of shear waves, including functional range and imperfection parameters, is shown through numerical simulations and graphical displays. The research also establishes boundaries for electrically short and open circumstances, taking into account the shear defect that exists between the inner and outer cylindrical layers.

Modeling the forced oscillations of a composite material cylinder in flow

Modeling the forced oscillations of a composite material cylinder in flow

Hetero‐blast from a structural reactive material cylinder under explosive loading

AbstractA structural reactive material (SRM) cylinder is considered here as a limiting case of a dense metallic energetic system in which a mixture of metal particles is consolidated to the theoretical maximum density excluding porosity, to possess both high energy density and mechanical strength. Dynamic fragmentation and free‐field explosion of a 103 mm inner diameter SRM cylinder charge is experimentally studied, with a wall thickness varying in a range of metal‐to‐explosive mass ratio M/C=1.3 to 4.0. Under explosive loading, the SRM cylinder produces a designated fragment size distribution divided into two groups: fine fragments with sizes on the order of 102 μm and below, and coarse fragments with sizes on the order ranging between 100‐101 mm. Prompt detonation shock‐induced reaction (DSIR) of the expanding cloud of high‐concentration fine fragments supplements the energy to enhance the primary blast as it propagates, while the coarse fragments form a high‐speed, high‐concentration metal momentum flux crossing the fireball and blast front to contribute to the total impulse loading to a nearby structure. Rapid impact‐induced reaction (IIR) of the secondary fragments from high‐speed coarse SRM fragments further enhances the reflected blast loading or generates a high interior explosion pressure as fragments perforate into the structure. The above distinctive characteristics of a unique hetero‐blast are coupled effectively in the near‐field range.

ПОСТРОЕНИЕ УПРУГОГО СОСТОЯНИЯ ТЕЛА В УСЛОВИЯХ ВТОРОЙ ОСНОВНОЙ ЗАДАЧИ ТЕОРИИ УПРУГОСТИ

The paper presents a mathematical model for constructing the stress-strain state of an anisotropic cylindrical body of a finite length with kinematic conditions specified on the body surface and the conditions being non-axisymmetric. The cylinder material is characterized by rectilinear transversal isotropy. The model is constructed on the basis of the boundary state method. The bases of the internal and boundary state spaces are formed and orthogonalized after which the desired elastic state is expanded in a Fourier series according to the elements of the orthonormal basis, the problem being to calculate the coefficients of the constructed series. A solution to the second fundamental problem of elasticity for a circular cylinder made of a hypothetical anisotropic large dark gray siltstone is presented. The accuracy of the solution is assessed and a graphical visualization of the result is provided.

Necking of thin-walled cylinders via bifurcation of incompressible nonlinear elastic solids.

Necking localization under quasi-static uniaxial tension is experimentally observed in ductile thin-walled cylindrical tubes, made of soft polypropylene. Necking nucleates at multiple locations along the tube and spreads throughout, involving the occurrence of higher-order modes, evidencing trefoil and fourth-foiled (but rarely even fifth-foiled) shaped cross-sections. No evidence of such a complicated necking occurrence and growth was found in other ductile materials for thin-walled cylinders under quasi-static loading. With the aim of modelling this phenomenon, as well as all other possible bifurcations, a two-dimensional formulation is introduced, in which only the mean surface of the tube is considered, paralleling the celebrated Flügge 's treatment of axially-compressed cylindrical shells. This treatment is extended to include tension and a broad class of nonlinear-hyperelastic constitutive law for the material, which is also assumed to be incompressible. The theoretical framework leads to a number of new results, not only for tensile axial force (where necking is modelled and, as a particular case, the classic Considère formula is shown to represent the limit of very thin tubes), but also for compressive force, providing closed-form formulae for wrinkling (showing that a direct application of the Flügge equation can be incorrect) and for Euler buckling. It is shown that the J2-deformation theory of plasticity (the simplest constitutive assumption to mimic through nonlinear elasticity the plastic branch of a material) captures multiple necking and occurrence of higher-order modes, so that experiments are explained. The presented results are important for several applications, ranging from aerospace and automotive engineering to the vascular mechanobiology, where a thin-walled tube (for instance an artery, or a catheter, or a stent) may become unstable not only in compression, but also in tension.