Deformation Of Liner Research Articles

Advanced natural gas storage system and verification tests of lined rock cavern - ANGAS project in Japan -

Technologies of an underground natural gas storage system, a Lined Rock Cavern (LRC) gas storage system called ANGAS (Advanced Natural GAs Storage), have been studied. The purpose of the project is to develop a suitable LRC system for Japan, and to contribute to expanding use of natural gas. It is necessary to study measures to shave off the daily peak load of natural gas through pipelines and it is expected that the ANGAS is one of key countermeasures for peak shaving. In the project, our goal is to ensure the design method of the LRC system under the Japanese geological conditions. One of the key technologies of the developed design method is based on plastic deformation of the steel liner considering the rock deformation appropriately. Using the developed design method and procedures, a small test cavern which is located at the Kamioka mine, the midland of Japan, was designed and constructed. The test cavern is surrounded by a sedimentary rock mass which consists of mainly sandstone and mudstone. The inner design pressure of the test cavern is 20MPa. In this paper, some results of the verification tests are presented and the validity of the LRC system for Japan is confirmed. Specifically, the steel liner was deformed up to its plastic zone, in order to be unified with the buffer material and the backfilled concrete as a hybrid structure. The displacements in the surrounding rock mass were stable under the inner design pressure 20MPa. Furthermore, the real crack intervals of the backfilled concrete are recognized to be less than the designed maximum interval and the real maximum crack width is inferred to be close to the designed one under 20 MPa pressure. Therefore, the design considering the crack properties of the back filled concrete has been verified.

Void-induced liner deformation and stress redistribution

Voids behind the liner may be created during or after construction of the tunnel liner because of insufficient backfilling, poor workmanship, water erosion or gravity. Survey on a number of tunnels that suffered collapse while in service showed that voids behind the liner were the main factors for the failure. The paper provides a better understanding of the stress redistribution that occurs in the rock mass around a void and quantifies the stresses induced in the liner due to the voids. The effects of cavities or voids due to different size, location and depth are explored numerically through an elasto-plastic finite element analyses. Other factors such as lining flexibility, in situ stresses and tunnel shape are also investigated. The analyses show that voids can induce a large change of the thrust and bending moment in the liner with respect to the case of a liner without a void. The bending moment can even reverse sign, which may result in cracks in the lining or even failure. The voids also change the distribution of the rock stresses around the tunnel, which may result in progressive failure of the rock and rock falls that can lead to additional damage to the liner. Because the void forms behind the liner, it may not be readily detected until significant damage to the liner has been produced, generally in the form of severe cracking, spalling or even failure.

Jet Velocity Profile of Linear Shaped Charges Based on an Arced Liner Collapse

The jet formation process of linear shaped charges (LSCs) heavily depends on the liner behavior before it collapses. The linear behavior includes the physical shape/deformation, material properties, the projection velocity before impact of the liner, etc. Due to the axially propagating detonation front along the charge, the interaction between the liner and detonation products is one of the important factors that controls the jetting process. In this study, the liner deformation (or arc) caused by the rarefaction is taken into account when analytically calculating the LSC jet velocity based on Birkhoff theory. Based on the formation of an arc in the liner, an analytical calculation of the jet velocity is accomplished in the detonation front, assuming that the entire liner is projecting at the same time. The arc of the LSC liner during projection, which was determined by fitting data generated from hydrocode simulations, allows a non-steady jetting profile. The analytical model described herein is compared to hydrocode simulation results and is shown to exhibit favorable results.

Shearography를 이용한 Aluminum Liner 내부 결함의 변형량과 변형율 측정 및 FEM 검증

Today, environmental issues have become a matter of worldwide concern. In particular, automobile industries engage in considerable research and investment to develop high-efficiency and ecofriendly cars. Most ecofriendly cars use natural gas or hydrogen gas instead of fossil fuels. In this regard, low-weight and high-pressure vessels have gradually been developed to increase the driving distance of a car. However, most pressure vessels installed in cars develop many defects over time owing to shocks sustained when the car is being driven. Such defects can cause the explosion of the pressure vessel. Therefore it is important to prevent such explosions due to internal defects. The use of shearography for measuring the internal defects of objects afford many advantages. It is a non-contact and non-destructive method, and it is not limited by the object shape. In this study, the internal defect deformation and strain of an aluminum liner that is used in a CNG bus for the fuel storage tank is measured using shearography. It is important to measure the strain and deformation in order to detect defects and repair the pressure vessel. To verify the accuracy of the shearography measurement method, the measurement results of shearography, out-of-plane ESPI, and FEM are compared quantitatively.

The influence of head diameter and wall thickness on deformations of metallic acetabular press-fit cups and UHMWPE liners: a finite element analysis

BackgroundTo increase the range of motion of total hip endoprostheses, prosthetic heads need to be enlarged, which implies that the cup and/or liner thickness must decrease. This may have negative effects on the wear rate, because the acetabular cups and liners could deform during press-fit implantation and hip joint loading. We compared the metal cup and polyethylene liner deformations that occurred when different wall thicknesses were used in order to evaluate the resulting changes in the clearance of the articulating region. MethodsA parametric finite element model utilized three cup and liner wall thicknesses to analyze cup and liner deformations after press-fit implantation into the pelvic bone. The resultant hip joint force during heel strike was applied while the femur was fixed, accounting for physiological muscle forces. The deformation behavior of the liner under joint loading was therefore assessed as a function of the head diameter and the resulting clearance. ResultsPress-fit implantation showed diametral cup deformations of 0.096, 0.034, and 0.014mm for cup wall thicknesses of 3, 5, and 7mm, respectively. The largest deformations (average 0.084±0.003mm) of liners with thicknesses of 4, 6, and 8mm occurred with the smallest cup wall thickness (3mm). The smallest liner deformation (0.011mm) was obtained with largest cup and liner wall thicknesses. Under joint loading, liner deformations in thin-walled acetabular cups (3mm) reduced the initial clearance by about 50%. ConclusionAcetabular press-fit cups with wall thicknesses of ≤5mm should only be used in combination with polyethylene liners >6mm thick in order to minimize the reduction in clearance.

Investigation of Controlling Welding Deformation of Steel Liner in Nuclear Power Station by Pre-stress Method

steel lining of nuclear power station implementing modular design,need dividing the circumference of cylinder of steel lining into a number of plate modules,and each module of cylinder is assembled and welded integrally after individually welding,but the radial welding displacement of plate edge of cylinder is not more than 2 mm.Therefore,by using the software of ABAQUS,the welding deformation of plate of cylinder are simulated with pre-stress,and design pre-stress tooling structure by oneself,test prestress of plate of cylinder and the radial deformation after welding.The results indicate that the welding process that firstly welding the axial angle steel,then exerting the pre-stress,lastly welding the circumferential angle steel,can obviously reduce the radial deformation of plate edge of cylinder,with the increment of pre-stress welding deformation is decreasing exponentially.When the top lift of oil cylinder reaches 18 MPa,the radial deformation of palate edge can control within 2.0 mm.

The Simulation Research on Assembly Deformation of Internal Combustion Engine Cylinder Liner

For the commonly used wet cylinder liner assembly characteristics and structure of water-cooled internal combustion engine, the influencing factors of wet cylinder liner deformation in the assembly conditions are calculated and analyzed using finite element method. Mainly from the matching stiffness of block-cylinder liner-gasket-cylinder head assembly, the local stiffness of the cylinder head, cylinder head bolt preload and the structure form of cylinder liner, get the influence laws of the various factors on the cylinder liner radial deformation and its each order Fourier series deformation, which provides guidance direction to control the cylinder liner deformation under assembly loading.

Finite Element Analysis and Optimization of S1110 Diesel Engine Body

In order to reduce the mass ratio of S1110 diesel engine, structural intensity and stiffness analysis are performed on the assembly parts of engine body by using the finite element method. Through comparative analysis of more than one calculation scheme, optimization scheme has been got. To ensure the intensity and stiffness of the engine body is not reduced under the premise, optimization scheme makes the body mass greatly reduced from the original engine body’s 38kg to 13.8kg and the engine mass ratio is reduced from 13.2kg/kW to 11.81kg/kW. The results show that, changing the body material from cast iron materials to cast aluminum materials, the body stress distribution trends are similar, but the cast aluminum body deformation increases; increasing the number of cylinder head bolts to 6 can reduce the deformation of the cylinder liner; a reasonable set of stiffeners can reduce the bearing bore deformation.

Piston seizure investigation: Experiments, modeling and future challenges

The complex problem of seizure failure of piston has been investigated experimentally with numerical simulation of thermal elasto-hydrodynamic lubrication (EHL). Metallurgical investigations in terms of chemical composition, chemical analysis and hardness were carried out for piston, rings and liner. In the thermal EHL model, an attempt has been made to include the complete physics of the problem. Boundary conditions in the piston secondary motion model were imported from finite element (FE) model (thermo-mechanical deformation of piston and liner) and engine conjugate heat transfer simulations using computational fluid dynamics (CFD). The FE and CFD model were validated experimentally. The predicted wear marks on piston and liner from the analysis compares well with the test results. Results suggest that high operating temperatures and significant reduction in thin film lubrication clearances accelerate the seizure failures. Further tests were conducted with coated piston to mitigate the high temperature effects. Future directions and challenges in terms modeling such complicated physics have been discussed. The authors believe that there exists a theoretical gap in modeling the seizure physics and hence, advanced theories should be developed to enhance the understanding of this complex seizure mechanism.

THD analysis of compliant journal bearings considering liner deformation

A numerical THD model is developed to investigate the effect of lining compliance on the bearing characteristics. The analysis shows increased load carrying capacity, significantly reduced peak pressures and thicker oil film in the loaded zone compared to a white metal bearing. Slightly thinner oil films are predicted at the bearing edges. Temperature and power loss are found to be similar for some load–speed combinations but higher for other operating conditions. It is also shown that load carrying capacity is more sensitive to thermal expansion while pressure and oil film thickness profiles are more sensitive to elastic deformation.

The Research on the Structure Parameters to Deformation of the 150 Diesel Engine Cylinder under Thermo-Mechanical Coupling

Finite element method with experimental data was used to calculate and analysis the temperature field and machine assembly of a 150 engine cylinder liner. Using a series of evaluation criteria such as maximum, minimum radius, light leakage rate to analyze the influence of the main structural parameters on the cylinder liner deformation in the coupling effect of Thermal stress and mechanical stress. Comparative results show that: increasing the wall thickness of cylinder liner can reduce the radial deformation of the cylinder liner effectively, the diameter of the cylinder liner shroud has little effect on the cylinder liner radial deformation, but it can reduce the local stress concentration of the cylinder liner, cylinder shroud thickness increases can lead to the radial deformation of the cylinder liner increasing.

Study on Thermal Stresses of Cylinder Liner’s Fabrication Using FEM Analysis

In the process of casing casting, great temperature gradient leads to contraction deformation of cylinder liner, which influences the quality of products. The thermal stresses caused by temperature gradient were analyzed by finite element method. The numerical results show that high equivalent Von Mises stress(242MPa) occurs in the surface zone of the cylinder liner as Cooling down to room temperature within pipe die ,also there is plastic deformation in the internal and external surface zone. Reducing the cooling speed, decreasing the temperature gradient and aging can reduce the influence of thermal stresses.

The Analysis of the Temperature Field and Deformation of Cylinder Liner Base on Finite Element Method and Experiment

The distortion of the cylinder liners of internal combustion engines has a significant affect on engine operation. It can affect the oil consumption, the blow-by, the wear behavior and, due to friction, the fuel consumption. In order to achieve future requirements regarding exhaust emissions and fuel consumption, the development of low distortion engine blocks will play a significant role. Finite element method with experimental data were used to calculate and analysis the temperature field and machine assembly of a 150 engine cylinder liner in this paper. It can provide a theoretical basis for the controlling of the cylinder liner deformation.

Type3 복합재료 압력용기의 복합재층 손상에 따른 영향성 평가를 위한 해석기법에 관한 연구

Type3 cylinder is a composite pressure vessel fully over-wrapped with carbon/epoxy composite layers over an aluminum liner, which is the most ideal and safe high pressure gas container for CNG vehicles due to the lightweight and the leakage-before-burst characteristics. During service in CNG vehicle, if a fiber cut damage occurs in outer composite layers, it can degrade structural performance, reducing cycling life from the original design life. In this study, finite element modeling and analysis technique for the composite cylinder with fiber-cut crack damage is presented. Because FE analysis of type3 cylinder is path dependant due to plastic deformation of aluminum liner in autofrettage process, method to introduce a crack into FE model affect analysis result. A crack should be introduced after autofrettage in analysis step considering real circumstances where crack occurs during usage in service. For realistic simulation of this situation, FE modeling and analysis technique introducing a crack in the middle of analysis step is presented and the results are compared with usual FE analysis which has initial crack in the model from the beginning of analysis. Proposed analysis technique can be used effectively in the evaluation of influence of damage on composite layers of type3 cylinder and establish inspection criteria of composite cylinder in service.

Deformation of metal-backed acetabular components and the impact of liner thickness in a cadaveric model

Shell deformation of resurfacing and all-metal modular cups following press-fit implantation has been reported, but not for conventional metal-backed cups with polyethylene liners. The deformation of acetabular components with historical and thin polyethylene inserts after press-fit insertion was evaluated using a cadaveric model. All shells and liners deformed upon implantation. Following joint loading, shell pinch decreased from 0.32 to 0.22 mm (p = 0.019) and from 0.29 to 0.13 mm (p = 0.003) for the thin and thick liner groups, respectively. Liner pinch also decreased from 0.17 to 0.04 mm (p = 0.031) and from 0.06 to 0 mm (p = 0.103) for the thin and thick liner groups, respectively. There were no significant differences between the thin and thick liners. Liner deformation was influenced by the initial shell deformation and donor bone quality. Shell and liner pinch decreased following joint loading, suggesting a settling in effect.

Controlling strain in geosynthetic liner systems used in vertically expanded landfills

According to relevant new regulations in China, a composite liner system involving geosynthetic materials must be installed at the bottom of an expanded landfill. The deformation and integrity of the composite liner under a variety of factors are important issue to be considered in the design of a landfill expansion. In this paper, we investigate the strain distribution in geosynthetic materials within the composite liner system of expanded landfills, including strains in geosynthetic materials resulting from overall settlement and lateral movement of landfills, localized subsidence in landfills, and differential settlement around gas venting wells. The allowable strains of geosynthetic materials are discussed based on the results of tensile tests, and the corresponding design criteria for composite liner systems are proposed. Meanwhile, practical measures allowing strain control in geosynthetic materials used in landfill engineering are proposed.

Clarification of the Amount of Machining Error Resulting from the Cutting Force and Thermal Expansion during the Cylinder Liner Boring Process

It is well known that the total machining errors of the engine cylinder liner are mainly dominated by the elastic deformation caused by the cutting force and the thermal expansion caused by the temperature rise during the boring process. Clarification of the amount of machining errors resulting from the cutting force and thermal expansion is useful for determining whether thermal expansion or the cutting force has a larger influence on machining errors during the boring process. This would provide a clear approach to the optimization of cutting conditions or to product improvement, leading to a higher degree of machining accuracy. In this paper, in order to clarify the amount of machining errors, the machining error caused by the thermal expansion apart from the elastic deformation of a cylinder liner caused by the cutting force was first determined. For this purpose, an experimental method is suggested in this paper. The temperature rise that causes the thermal expansion of the cylinder liner was simulated by a YAG laser heating process instead of by an actual boring process. During this heating process, the machining errors caused by the thermal expansion could be solely investigated. First, an actual cylinder boring process was performed (cutting speed: 900 m/min, feed rate: 0.2 mm/rev, depth of cut: 0.3 mm, dry cutting). The total machining errors caused by the cutting force and thermal expansion were measured. Then, the YAG laser heating experiment was also carried out. Comparing the results between the two experiments, it was clarified that the thermal expansion of the cylinder liner caused by the cutting energy is dominant and the deflection caused by the cutting force is small.

大型クロスヘッドディーゼル機関のシリンダライナの変形―計算値と計測値の比較

An investigation was made into the deformation of a cylinder liner used in a large crosshead diesel engine. This deformation was calculated, but also measured. The results were then compared. They were not perfectly coincidental. The reason for the discrepancy is considered as applying the axis symmetrical model to a cylinder block being a complicated shape, inaccurate temperature distribution and improper modeling of the contact surfaces of the parts.

414 段板紙の罫線特性における下平板変形に及ぼす溝型形状の影響(GS3,一般セッション:GS3 加工・計測)

414 段板紙の罫線特性における下平板変形に及ぼす溝型形状の影響(GS3,一般セッション:GS3 加工・計測)

Possible use of vacuum controlled pulsators for sheep milking machines

Comparison measurements and evaluation of the suitability of three pulsators for sheep milking machines were carried out, i.e. a prototype made by the manufacturer of the milking parlour of the pulsator ratio 50% (50:50) and two hydraulic pulsators of the Danish manufacturer S.A. Christensen (SAC), models Unipuls-2 of the pulsator ratios 50% (50:50) and 60% (60:40). The specified pulsation rate was 2.5/s(150/min). It was found that the pulsator prototype made by the milking parlour manufacturer slowly passed air, whereby the vacuum in pulsation chambers did not attain the maximum value. Fig. 2 illustrates the operation of this pulsator. Both SAC pulsators had better parameters and their pulsograms are plotted in Figs. 3 and 4. Also the measurements of a liner deformation in dependence on the vacuum in the teatcup pulsation chamber were made based on which the moment of a real liner opening, i.e. at the vacuum of 35 kPa was determined. The results obtained by the experiments carried out can be summed up as follows: As the change in pulsation rate does not affect the time of transition phases “a” and “c”, the intervals “b” and “d” are shorter if the pulsation rate is increased. Interval “b”, i.e. a full liner opening, shortens with the rising rate and extends with the increased value of the pulsator ratio. For this reason higher pulsator ratios should be used at very high pulsation rates. The teatcup operation depends on the physical-mechanical properties of the liner used. On the milking unit measured considerable differences in time take place between the interval “b” and the liner full opening due to a relatively high resistance power of the liner to deformation. The pulsator prototype designed by the milking parlour producer revealed as fully unsuitable based on its pulsogram. As far as the time of the liner opening is concerned, its parameters were worse than on both SAC pulsators, however, we cannot indicate it as unsuitable.