Deformation Of Cylinder Research Articles

Patterns of Alloy Deformation by Pulsed Pressure

Patterns of alloy deformation for optimization of a welding regime are studied by the method of modeling and deformation profiles providing high deformation quality are determined. A model of stepwise kinetics of the alloy deformation by pulsed pressure from the expanding plasma channel inside of a deformable cylinder is suggested. The model is based on the analogy between the acoustic and electromagnetic wave processes in long lines. The shock wave pattern of alloy deformation in the presence of multiple reflections of pulsed pressure waves in the gap plasma channel – cylinder wall and the influence of unloading waves from free surfaces are confirmed.

Distribution of ring pressure over a worn cylinder liner surface

A trial to define the effect of changes in cylinder geometry on compression ring pressure distribution has been presented in this paper which refers to the earlier papers of the authors. The analysis encompasses these cylinders where both circumferential and axial deformations occurred, relative to constructional and assembly errors but above all to engine operation. The conclusions withdrawn from these analyses were applied to exemplary calculations that try to evaluate the effect of cylinder deformation on correct collaboration of ring and liner and particularly on possibility of circumferential gaps leading to blow-by. The drafts presented in the paper show exemplary results of ring pressure distribution for a complete ring path between the dead centers and selected engine operational data. Moreover, such areas of cylinder surface were shown where slots between compression ring and cylinder liner might occur with high probability.

Effects of U-notches on the dynamic fracture and fragmentation of explosively driven cylinders

Metal cylinder specimens are explosively expanded to fragmentation and the effect of U-notches in walls are investigated on fragmentation behaviors and failure mechanisms of the cylinders experimentally and numerically. Fragments were recovered by sawdust and sorted into four categories according to fragment morphology and fracture mode. The shear fracture is pronounced in the low notch depth condition, while tensile fracture plays a leading role in higher notch depth. Moreover, mass percentage distribution of the fragments appears more affected by the notch depth than width. In addition, fragmentation energy and fragmentation toughness, considered as material properties, are discussed using Grady’s energy-based theory. A suitable correction factor related to the width and depth of the notch is proposed to depict the effects of the U-notch. The effects of U-notches on the deformation and fracture behavior of cylinders are discussed with numerical simulations, indicating the stress concentration was noticeable at the notch tip, and the dynamic stress concentration factor (SCF) of the U-notch was less than that of the V-notch.

Cylinder deformations in orbit closures of translation surfaces

Let M be a translation surface. We show that certain deformations of M supported on the set of all cylinders in a given direction remain in the GL(2,R)-orbit closure of M. Applications are given concerning complete periodicity, field of definition, and the number of of parallel cylinders which may be found on a translation surface in a given orbit closure. The proof uses Eskin-Mirzakhani-Mohammadi's recent theorem on orbit closures of translation surfaces, as well as results of Minsky-Weiss and Smillie-Weiss on the dynamics of horocycle flow.

Analysis of Welding Process for Automotive Rear Cradle

A rear cradle as one of the suspension system takes a role to connect a tie rod, suspension arm, transmissions and rubber bush. It consists of the side member and cross member which are joined by welding process. However, the rear cradle may be distorted due to thermal deformation during welding process, which cause dimensional tolerance problem when assembling. So, it is necessary to predict the thermal deformation and the optimal welding conditions should be suggested to reduce the dimensional tolerances. In this paper, MAG(metal active gas) welding process was applied in the simulation model using the SYSWELDR, commercial S/W for welding simulation. And then, It should be predicted on the results about the gap and thermal deformation of main cylinder and derived the phase transformation, temperature distribution, residual stress and thermal deformation of total model shape.

Numerical simulations of the early stages of high-speed droplet breakup

Experiments reported in the literature are reproduced using numerical simulations to investigate the early stages of the breakup of water cylinders in the flow behind normal shocks. Qualitative features of breakup observed in the numerical results, such as the initial streamwise flattening of the cylinder and the formation of tips at its periphery, support previous experimental observations of stripping breakup. Additionally, the presence of a transitory recirculation region at the cylinder’s equator and a persistent upstream jet in the wake is noted and discussed. Within the uncertainties inherent to the different methods used to extract measurements from experimental and numerical results, comparisons with experimental data of various cylinder deformation metrics show good agreement. To study the effects of the transition between subsonic and supersonic post-shock flow, we extend the range of incident shock Mach numbers beyond those investigated by the experiments. Supersonic post-shock flow velocities are not observed to significantly alter the cylinder’s behavior, i.e., we are able to effectively collapse the drift, acceleration, and drag curves for all simulated shock Mach numbers. Using a new method that minimizes noise errors, the cylinder’s acceleration is calculated; acceleration curves for all shock Mach numbers are subsequently collapsed by scaling with the pressure ratio across the incident shock. Furthermore, we find that accounting for the cylinder’s deformed diameter in the calculation of its unsteady drag coefficient allows the drag coefficient to be approximated as a constant over the initial breakup period.

Steady Bifurcating Solutions of the Couette–Taylor Problem for Flow in a Deformable Cylinder

The classical Couette–Taylor problem is to describe the motion of a viscous incompressible fluid in the region between two rigid coaxial cylinders, which rotate at constant angular velocities. This paper treats a generalization of this problem in which the rigid outer cylinder is replaced by a deformable (nonlinearly elastic) cylinder. The inner cylinder is rigid and rotates at a prescribed angular velocity. We study steady rotationally symmetric motions of the fluid coupled with steady axisymmetric motions of the deformable outer cylinder in which it rotates at a prescribed constant angular velocity, typically different from that of the inner cylinder. The motion of the outer cylinder is governed by a geometrically exact theory of shells and the motion of the liquid by the Navier–Stokes equations, with the domain occupied by the liquid depending on the deformation of the outer cylinder. The nonlinear fluid-solid system admits a (trivial) steady solution, termed the Couette solution, which can be found explicitly. This paper treats the global (multiparameter) bifurcation of steady-state solutions from the Couette solution. This problem exhibits technical mathematical difficulties directly due to the fluid-solid interaction: The smoothness of the shell’s configuration restricts the smoothness of the fluid variables, and their boundary values on the shell determine the smoothness of the shell’s configuration. It is essential to ensure that this cycle of implications is consistent.

发射望远镜的设计与装调

On the structure characteristics of emission telescopes, this paper designs and assembles a 270 mm Mersenne reflecting afocal Cassegrain transmitter-telescope to achieve the laser emission and laser collimation. Firstly, the design method for an on-axis reflected system was determined and its system parameters were given. Based on the finite element method, the deformations of cylinder and truss primary mirror supporting structures and that of the three-beam and four-beam secondary mirror support structures were analyzed in the different working conditions, and the three-beam secondary mirror support structure and the truss structure were chosen to be used in the telescope. Furthermore, systematic optical aberration caused by the secondary mirror decentration was analyzed by adjusting primary and secondary mirror structures with the help of an interferometer and an autocollimation plane mirror and a sensitivity matrix was obtained to assembly, adjust and test the system. Finally, obtained results show that the systematic wavefront aberration RMS and PV are 0.146 7, and 0.739 41 respectively. It is proved that the design of the transmitter-telescope has a better imaging quality and satisfies the requirements of the optical design and laser emission.

Boundary conditions for axisymmetric piezoelectric cylinder

For axisymmetric piezoelectric cylinder, the reciprocal theorem and the axisymmetric general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the cylinder of general edge geometry and loadings. A decay analysis technique developed by Gregory and Wan is converted into necessary conditions on the end-data of axisymmetric piezoelectric circular cylinder, and the rapidly decaying solution is established. The prescribed end-data of the circle cylinder must satisfy these conditions in order that they could generate a decaying state within the cylinder. When stress and mixed conditions are imposed on the end of cylinder, these decaying state conditions for the case of axisymmetric deformation of piezoelectric cylinder are derived explicitly. They are then used for the correct formulation of boundary conditions for the theory solution (or the interior solution) of axisymmetric piezoelectric cylinder. The results of the present paper enable us to establish a set of correct boundary conditions, most of which are obtained for the first time.

Discrete modeling of granular soils reinforcement by plant roots

The analysis of the influence of the roots on the shear resistance of the soil requires identifying the effect of the different root–soil interaction processes depending on soil and roots properties. For that purpose, a numerical model of direct shear tests of non-rooted and rooted granular soils based on the Discrete Element Method was developed. The soil is modeled as an assembly of locally interacting spheres and the roots are modeled as deformable cylinders in the soil matrix. The model allows accounting for the root tensile loading until breakage, the root bending loading, the root–soil adhesive links until adhesion breakage, the root slippage associated with a frictional resistance at the root–soil interface.The study focuses on identifying the different root–soil interaction mechanisms depending on the soil type. Both frictional and cohesive granular soil types were used in the simulations. The effects of the roots mechanical properties – tensile, bending modulus and root–soil interfacial friction angle – and of the root number were also analyzed for the different soil types.The results first show that the effect of the roots strongly depends on the shear strain for any soil type. For frictional soils, an increasing shear strain induces progressively a pure tensile loading of the roots until slippage of the root–soil interface. For cohesive granular soils, the pure tensile loading of the roots is followed by a progressive breakage of the adhesive root–soil links and by a complete slippage of the roots. The results show that the influence of the root number is significant if the prevailing processes are root tensile loading combined with slippage whereas it is less important if root loading is combined with progressive breakage of the adhesive links for the root configurations explored. Finally, the results show that the shear strain range associated with the different processes strongly depends on the relative rigidities of the roots and soil matrix.The model developed was shown of great interest to analyze the shear resistance of the rooted soil assemblies depending on the shear strain. Such an approach could therefore be used to test the different assumptions done in the analytical models. Developing analytical models of slope stability based on the calculation of the shear resistance of rooted soil depending not only on soil and root properties but also on shear strain intensity also constitutes a perspective for the use of the model developed.

An analysis of phenomena accompanying ring collaboration with worn cylinder surface

The presented study which refers to the earlier papers of the authors discusses an effect of cylinder wall deformation on the effectiveness of compression ring operation. Presented models permit a mathematical description of a deformed cylinder and definition of ring wall pressure relative to these deformations. The drafts presented in the paper, obtained in a course of calculations of a compression ring installed in a work machine engine, allow to evaluate the effect of cylinder deformations on distribution of ring circumferential pressure and point out areas where the light slots could occur.

Verification of magnetorheological shock absorber models with various piston configurations

In this study, a mathematical model of a monotube magnetorheological (MR) shock absorber is presented and verified with an emphasis on leakage flow mechanisms and their impact on the damping force output. The model can be used in shock absorber design studies as well as vehicle simulations. To copy the force increase with yield stress, the authors employed the generic biplastic Bingham model for capturing the hydraulic resistance of the annular flow path in the piston. Moreover, the authors considered the impact of high-speed losses, fluid chamber compressibility, cavitation, elastic deformation of cylinder, fluid inertia, floating piston inertia, gas chamber pressure and Coulomb friction between damper components and the cylinder. The presented MR shock absorber model of is verified against experimental data involving three prototype shock absorber units. One shock absorber unit was a conventional unit with only one annular flow path, the second one employed the thru-core flow bypass for force roll-off at low piston velocities. The third unit utilized a so-called flux bypass to lower the magnetic field strength in the annulus to initiate the flow of MR fluids at lower yielding pressures across the piston. The flux bypass was located in the annulus. Except for the bypass features, all units were identical. All secondary flow features affect on the damping force at low piston velocities in particular. The experiment covered all key flow regimes of MR shock absorber operation from low speed to high speed. The results show that the proposed approach is capable of capturing key characteristics across the examined range of piston velocities and coil current levels.

Study on Deformation of Steel Cylinder during Artificial Island Construction

A model is founded to simulate the process of artificial island construction by numerical analysis method. The displacement and deformation of the steel cylinder are analyzed. From the results, the settlement of steel cylinder is great, and the maximum is 28.5cm. At the same time, the steel cylinder has lateral displacement in the process of the island construction. The maximum lateral displacement is 12cm. The major influencing factor to the deformation of steel cylinder is the construction of filling sand inside and outside of island and flinging stone. Therefore, the settlement and displacement of steel cylinder should be monitored nearly during this construction step.

Plastic Deformation Behavior of High Strength Cast Aluminium Cylinder in Hot Power Backward Spinning

The hot power backward spinning(HPBS) of the high strength cast aluminums (HSCA) cylinder is a complex metal forming process. To analysis the plastic deformation of HSCA cylinder in HPBS process, a 3D coupled thermo-mechanical FE model of the process was built under the ABAQUS/explicit environment based on the solution of several key techniques, such as heat boundary condition treating, material properties definition, ALE adaptive meshing technology, etc., and verified by theoretical evaluation. Then simulation and analysis of HPBS of the process were carried out. The results show that the strain gradient which leads to the serious inhomogeneous deformation is produced in the thickness direction of the workpiece during the process.

G031102 鋼円筒の高速衝撃内圧破壊および変形特性([G031-10]材料力学部門,一般セッション : 圧力容器,円筒)

The ensuring safety for damages from high-speed shock phenomena has been required in air-conditioning machine field, and the establishment of evaluation techniques is expected. In this study, the fracture characteristic and deformation behavior of SPHE (Steel plate hot deep-drawn extra) steel cylinders was examined as a preliminary study. SPHE steel cylinders were expanded with high strain rate by PETN (Pentaerythritol tetranitrate) explosive. SPHE used for a typical refrigerant circuit component like a compressor has relatively higher ductility among carbon steels. The deformation of cylinders was observed by high speed camera and the fractures were evaluated from the fragments after high-speed shock test. Numerical analyses were also made to evaluate the high-speed shock deformation phenomena.

The generation of jet and mixing induced by the interaction of shock wave with R22 cylinder

Based on the large eddy simulation, combined with the 5th order weighted essentially non-oscillatory scheme and the immersed boundary method, the shock wave interacting with an R22 cylinder is numerically simulated. Our numerical results present clearly the deformation of cylinder induced by the Richtmyer-Meshkov instability due to the interaction of shock wave with R22 cylinder, which accords well with previous experimental results of Haas and Sturtevant [Haas J F and Sturtevant B 1987 J. Fluid Mech. 181 41]. In addition, the numerical results reveal the generation process of a jet induced by the refracted shock focusing near the right interface of the inner cylinder, as well as the roll-up of the secondary vortexes along the slip layer of two main vortexes. The mixing mechanism of R22 gas and air is also expatiated. Furthermore, the evolution of R22 cylinder under reshock condition is numerically simulated with two different end wall distances. For the long distance case, the reflected wave interacts with severely distorted R22 volume, making it further compressed on the x-axis. While for the small case, two Mach reflections occur between the reflected shocks during their propagating upstream within the cylinder. The two high pressure areas behind two triple points can accelerate the boundary of the R22 cylinder while they are passing through it and induce two jets.

Thermoelastic Dynamic Behaviors of a FGM Hollow Cylinder Under Non-Axisymmetric Thermo-Mechanical Loads

AbstractThis paper is concerned with two-dimensional (r, θ) thermoelastic dynamic responses of a long functionally graded hollow cylinder subjected to asysmmetrical thermal and mechanical loads. The material properties, except the Poisson's ratio, are assumed to be temperature independent and vary exponentially and continuously in the radial direction. By means of finite difference method and Newmark method, the motion governing equations of the long FGM hollow cylinder are solved. Comparisons between this paper's results and the corresponding analytical results validate the proposed solution. In addition, the effects of the volume fraction, temperature boundary conditions on the hollow cylinder's deformations and stresses distributions are examined, and many other valuable thermoelastic dynamic characteristics are revealed.

Radial Deformation of Cylinders Due to Torsion

Classical literature on solid mechanics claims existence of radial deformation due to torsion but there is hardly any literature on analytic solutions capturing this phenomenon. This paper tries to solve this problem in an asymptotic sense using the variational asymptotic method (VAM). The method makes no ad hoc assumptions and hence asymptotic correctness is assured. The VAM splits the 3D elasticity problem into two parts: A 1D problem along the length of the cylinder which gives the twist and a 2D cross-sectional problem which gives the radial deformation. This enables closed form solutions, even for some complex problems. Starting with a hollow cylinder, made up of orthotropic but transversely isotropic material, the 3D problem has been formulated and solved analytically despite the presence of geometric nonlinearity. The general results have been specialized for particularly useful cases, such as solid cylinders and/or cylinders with isotropic material.

Pressure distribution in an elastomer confined by a long thin-walled flexible hollow cylinder under the assumption of a hydrostatic stress state

The stress distribution in a pressurized elastomer confined by a hollow cylinder is of interest in various applications of material testing and manufacturing. A relatively accurate closed form solution for the pressure distribution inside an elastomer confined by a rigid hollow cylinder was presented by Yu et al. (2001). But in many practical applications the assumption of a rigid hollow cylinder is not appropriate, because the cylinder deformations have a significant influence on the stresses inside the elastomer. Thus in this paper a solution for an elastomer confined by a deformable hollow cylinder is derived. Both axial and radial deformations of the hollow cylinder are taken into account, while the bending stiffness of the cylinder wall is neglected, i.e. the cylinder wall is treated according to the membrane theory. The accuracy of the proposed closed form solution is verified by a parametric finite element simulation.

Theoretical Analysis on Mechanical Deformation of Membrane-Based Photomask Blanks

Membrane-based photomask is used in proximity X-ray lithography including that in LIGA (Lithographie, Galvanoformung und Abformung) process, and near-field photolithography. In this article, out-of-plane deformation (OPD) and in-plane displacement (IPD) of membrane-based photomask blanks are theoretically analyzed to obtain the mask blanks with flat front surface and low stress absorber film. First, we derived the equations of OPD and IPD for the processing steps of membrane-based photomask such as film deposition, back-etching and bonding, using a theory of symmetrical bending of circular plates with a coaxial circular hole and that of deformation of cylinder under hydrostatic pressure. The validity of the equations was proved by comparing the calculation results with experimental ones. Using these equations, we investigated the relation between the geometry of the mask blanks and the distortions generally, and gave the criterion to attain the flat front surface. Moreover, the absorber stress-bias required to obtain zero-stress on finished mask blanks was also calculated and it has been found that only little stress-bias was required for adequate hole size of support plate.