Increasing Plate Thickness Research Articles

Numerical simulation and experimental investigation of structural optimization of capacitance sensors for measuring steam wetness with different coaxial cylinders

Steam wetness is an important parameter, which is difficult to measure accurately. A simulation study is performed based on the theories of electrodynamics and hydrodynamics to investigate the characteristics of wetness capacitance sensors with different coaxial cylinders, and an experimental system and two capacitance probes were designed to measure steam wetness. Using a FLUENT user defined function (UDF) code, a program to compute the electric field was compiled which can transmit the data between the electric field and the flow field. The coupling of the steam flow field and the electric field within the sensors is investigated through numerical simulation. The results show that the electric field intensity decreases from the inner electrode plate to the outer electrode plate. The electric field intensity near the inner plate increases with increasing plate thickness while the sensor length has no effect on the electric field intensity distribution in the radial direction, but the peak electric field intensity decreases with increasing sensor length. The peak electric field intensity weakens with increasing electrode separation. Comparison of the numerical simulation results and the experimental results shows that the results of the simulation are similar to those of the experiments, with the output capacitance fluctuating around a fixed value as the steam flow rate changes and increasing linearly with increasing wetness. The maximum difference between the experimental data and the numerical simulation data is 0.78nF, which is a discrepancy of 19.8%.

Three-Dimensional Stress Concentration Factor in Finite Width Plates with a Circular Hole

The three-dimensional stress concentration factor (SCF) at the edge of elliptical and circular holes in infinite plates under remote tension has been extensively investigated considering the variations of plate thickness, hole dimensions and material properties, such as the Poisson’s coefficient. This study employs three dimensional finite element modeling to numerically investigate the effect of plate width on the behavior of the SCF across the thickness of linear elastic isotropic plates with a through-the-thickness circular hole under remote tension. The problem is governed by two geometric non-dimensional parameters, i.e., the plate half-width to hole radius (W/r) and the plate thickness to hole radius (B/r) ratios. It is shown that for thin plates the value of the SCF is nearly constant throughout the thickness for any plate width. As the plate thickness increases, the point of maximum SCF shifts from the plate middle plane and approaches the free surface. When the ratio of plate half-width to hole radius (W/r) is greater than four, the maximum SCF was observed to approximate the theoretical value determined for infinite plates. When the plate width is reduced, the maximum SCF values significantly increase. A polynomial curve fitting was employed on the numerical results to generate empirical formulas for the maximum and surface SCFs as a function of W/r and B/r. These equations can be applied, with reasonable accuracy, to practical problems of structural strength and fatigue, for instance.

Design of large vacuum chamber for VEC superconducting cyclotron beam line switching magnet

VEC K500 superconducting cyclotron will be used to accelerate heavy ion. The accelerated beam will be transported to different beam halls by using large switching magnets. The vacuum chamber for the switching magnet is around 1000 mm long. It has a height of 85 mm and width varying from 100 mm to 360 mm. The material for the chamber has been chosen as SS304.The material for the vacuum chamber for the switching magnet has been chosen as SS304. Design of the vessel was done as per ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. It was observed that primary stress values exceed the allowable limit. Since, the magnet was already designed with a fixed pole gap; increase of the vacuum chamber plate thickness restricts the space for beam transport. Design was optimized using stress analysis software ANSYS. Analysis was started using plate thickness of 4 mm. The stress was found higher than the allowable level. The analysis was repeated by increasing plate thickness to 6 mm, resulting in the reduction of stress level below the allowable level. In order to reduce the stress concentration due to sharp bend, chamfering was done at the corner, where the stress level was higher. The thickness of the plate at the corner was increased from 6 mm to 10 mm. These measures resulted in reduction of localized stress.

A size-dependent functionally graded sinusoidal plate model based on a modified couple stress theory

A size-dependent model for bending and free vibration of functionally graded plate is developed based on the modified couple stress theory and sinusoidal shear deformation theory. In the former theory, the small scale effect is taken into consideration, while the effect of shear deformation is accounted for in the latter theory. The equations of motion and boundary conditions are derived from Hamilton’s principle. Analytical solutions for the bending and vibration problems of simply supported plates are obtained. Numerical examples are presented to illustrate the influences of small scale on the responses of functionally graded microplates. The results indicate that the inclusion of small scale effects results in an increase in plate stiffness, and consequently, leads to a reduction of deflection and an increase in frequency. Such small scale effects are significant when the plate thickness is small, but become negligible with increasing plate thickness.

A size-dependent functionally graded Reddy plate model based on a modified couple stress theory

In this paper, a size-dependent model for bending and free vibration of functionally graded Reddy plate is developed. The present model accounts for both small scale and shear deformation effects in functionally graded microplates. The small scale effects are captured using the modified couple stress theory, while the shear deformation effects are included using the third-order shear deformation theory. The equations of motion and boundary conditions are derived from Hamilton’s principle. Analytical solutions are obtained for a simply supported plate. Numerical examples are presented to illustrate the effects of small scale on the responses of microplates. The results reveal that the inclusion of small scale effects results in an increase in plate stiffness, and consequently, leads to a reduction of deflection and an increase in frequency. Such small scale effects are significant when the plate thickness is small, but become negligible with increasing plate thickness.

An equivalent single-layer approach for free vibration analysis of smart laminated thick composite plates

An equivalent single-layer model for the free vibration analysis of smart laminated plates is presented. The electric and magnetic fields are assumed to be quasi-static, and third order in-plane kinematics is employed to adequately take the shear influence into account when the plate thickness increases. The model governing equations are the plate equations of motion written in terms of mechanical primary variables and effective stiffness coefficients, which take the multi-field coupling effects into account. The model shows that the surface magneto-electric boundary conditions enter the definitions of the laminate forces and moment resultants. Moreover, it reveals that new stiffness terms, which are related to the derivatives of the transverse displacement component and are exclusively associated with the piezoelectric and piezomagnetic couplings, are involved. Free vibration solutions for simply supported plates are presented to validate the model by comparing the present results with benchmark 3D solutions. Comparison of the results obtained by lower order models, namely zero and first order shear deformation theories, is presented and discussed, focusing on the adequateness of the obtained models with respect to the plate thickness. Some characteristic features of smart laminate behavior have also been addressed.

Effect of plate thickness on bending radius and energy dissipation at the subduction zone hinge

Despite the thickness of subducting oceanic plates being identified as a control on slab and hinge behavior during subduction, there have been few attempts to quantify its effect with fully dynamic models. This paper presents a series of dynamic laboratory experiments of progressive subduction of a narrow plate into an upper mantle reservoir in which plate thickness is systematically varied from 4 mm (scaling to 20 km), up to 24 mm (120 km). The experiments investigate its effect on bending radius, subduction kinematics and the rate of energy dissipated at the hinge as a percentage of the total potential energy released through subduction. The bending radius of the hinge is found to have a strong linear relationship with plate thickness, where an increase in plate thickness corresponds to an increase in bending radius. Subduction velocity increases with plate thickness due to the increased negative buoyancy of thicker slabs, which is not compensated for by any significant increase in mantle drag on the slab. This increase is almost entirely accommodated by an increase in trench retreat rate, with a fivefold increase over the whole thickness range, while subducting plate velocity remains relatively constant. The energy dissipation ratio (ΦBe/ΦBu) is low across all plate thicknesses, with the plates falling within a range of ∼4–10% during steady state subduction. The models show a moderate trend toward decreasing ΦBe/ΦBu with increasing plate thickness.

Research on Structural Strength of Catamaran Superstructure Constructed with Aluminum Alloy

The design of Superstructure constructed with aluminum alloy do not have to follow the traditional standard design method. It can be designed by applying strength theory and ANSYS program or MSC Patran / Nastran program, which can ensure the strength requirements with the selected aluminum alloy components and make the weight of the ship lightest. In this paper, the 42.4m catamaran sightseeing boat is used as an example. The structural strength of the superstructure constructed with aluminum alloy is calculated by MSC Patran / Nastran program. The distribution of the superstructure stress is obtained, which proved the size of the selected components of the superstructure can meet the requirements of the local strength and can be the reference of selecting the structure size. As the other conditions are unchanged, the the local thickness of the junction of the front wall and the side wall of the compass deck is changed. the relationship between plate thickness and stress is obtained. It is found that as The plate thickness is thicker, the stress there decreases; and as the thickness is smaller, it is obvious to reduce stress as the plate thickness Increase. when the thickness increases to a certain extent, the effect of the plate stress decreases is not obvious.

Residual stress study of welded high strength steel thin-walled plate-to-plate joints, Part 1: Experimental study

In this study, an investigation on the residual stress distributions near the weld toe of high strength steel thin-walled plate-to-plate T and Y-joints is carried out. Two groups of specimens, corresponding to welding preformed at ambient temperature and at a preheating temperature of 100°C, are fabricated. The effects of preheating and joint geometry on the residual stress distribution near the weld toe are investigated by using the ASTM hole-drilling method. Furthermore, a study is also performed to evaluate the influence of brace plate cutting on the residual stress distribution near the weld toe of the joints. Experimental results obtained shown that tensile residual stress up to one third of the yield strength could appear near the weld toe and its value increases as the plate thickness and intersection angle increase. Furthermore, preheating was found to be an effective way to reduce the magnitude of residual stress while brace plate cutting could release the residual stress along the weld toes significantly.

High-Frequency Inducting Plate Bending Forming with Gravity on Different Thickness Ship Plate

In this article, a FEM model of high-frequency induction bending with gravity is established and with which the heated temperature, stress, deformation, residual stress and bending angle after cooling, etc are studied on different thickness ship plate. The results show that the steel plate can be heated to 860 above the austenitic temperature. Heating temperature is gradually decreased as the thickness increase, while there is a fluctuation in the late. As the plate thickness increases, in mm, the bending angle of the plate gradually decreases, and gradually increases in 8mm14mm, and then decreases in the late. Under the given heating conditions, thin plate and the mm thick plate have the best result of deformation. The stress in heat area reaches to the yield stress of Q345, and promotes plastic deformation due to the role of heating temperature gradient and gravity. When the plate has cooled, the residual stress is mainly concentrated at the bottom of the coil.

高速固相接合した2024アルミニウム合金スタッドと6N01アルミニウム合金板の界面組織と機械的性質

2024-T3 aluminum alloy studs were welded to 6N01-T6 aluminum alloy plates by using an advanced high-speed solid-state joining method. Plastic deformation of a projection was promoted with increasing discharge voltage. As the result, joining area and joint strength increased. Fracture stress was about 300 MPa in all discharge voltage. In the case of thin plate, the outside region was subjected to higher temperature than the inside region, which caused asymmetrical deformation. In contrast, the deformation was symmetrical in the case of thick plate, because temperature similarly rose in both inside and outside. This resulted in the increased joining area and joint strength with increasing plate thickness. Vickers hardness profile was also measured across the weld interface. The softened zone was appeared at the 6N01-T6 aluminum alloy plate adjacent to the weld interface. Hardness of the softened zone was recovered to that of 6N01-T6 aluminum alloy after post-weld aging. This result indicated that softening was caused by dissolving β″precipitates in the aluminum matrix due to the welding heat input.

High Velocity Impact Damage Analysis for Glass Epoxy-Laminated Plates

The ultimate objective of the current work is to examine the effect of thickness on fiberglass reinforced epoxy matrix subjected to high velocity impact loading. The composite material chosen for this research was from type C-glass/epoxy 200 g/m2and type C-glass/epoxy 600 g/m2. This material is used as a composite reinforcement in high performance applications since it provides certain advantages of specific high strength and stiffness as compared to metallic materials. This study investigates the mechanical properties, damage characterisation and impact resistance of both composite structures, subjected to the changes of impact velocity and thickness. For mechanical properties testing, the Universal Testing Machine (UTM) was used while for the high velocity impact, a compressed gas gun equipped with a velocity measurement system was used. From the results, it is found that the mechanical properties, damage characterisation and impact resistance of type C-glass/Epoxy 600 g/m2posses better toughness, modulus and penetration compared to type C-glass/Epoxy 200 g/m2. A general trend was observed on the overall ballistic test results which indicated that as the plate specimen thickness continues to increase, the damage at the lower skin decreases and could not be seen. Moreover, it is also found that, as the plate thickness increases, the maximum impact load and impact energy increases relatively. Impact damage was found to be in the form of perforation, fibre breakage and matrix cracking. Results from this research can be used as a reference in designing structural and body armour applications in developing a better understanding of test methods used to characterise impact behaviour.

The Effect of Weld Profile and Geometries of Butt Weld Joints on Fatigue Life Under Cyclic Tensile Loading

The fatigue life of welded joint was calculated based on numerical integration of simple Paris’ law and a reliable solution of the stress intensity factor (SIF). The initial crack length (ai) was assumed to be equal to 0.1 mm in case of weld toe. This length was satisfactory for different butt joints geometries. The comparisons with the available data from standards and literature were demonstrated. It was shown numerically that the machining of weld reinforcements will increase the fatigue life. The increase of plate thickness decreases the fatigue strength (FAT) and the number of cycles to failure when using the proportional scaling of crack length. The validation processes of the current calculations have been shown. Therefore, it can be concluded that it will prevent the unnecessary waste of time consumed to carry out the experiments.

Biological aspects of early osteoarthritis

Early OA primarily affects articular cartilage and involves the entire joint, including the subchondral bone, synovial membrane, menisci and periarticular structures. The aim of this review is to highlight the molecular basis and histopathological features of early OA. Selective review of literature. Risk factors for developing early OA include, but are not limited to, a genetic predisposition, mechanical factors such as axial malalignment, and aging. In early OA, the articular cartilage surface is progressively becoming discontinuous, showing fibrillation and vertical fissures that extend not deeper than into the mid-zone of the articular cartilage, reflective of OARSI grades 1.0-3.0. Early changes in the subchondral bone comprise a progressive increase in subchondral plate and subarticular spongiosa thickness. Early OA affects not only the articular cartilage and the subchondral bone but also other structures of the joint, such as the menisci, the synovial membrane, the joint capsule, ligaments, muscles and the infrapatellar fat pad. Genetic markers or marker combinations may become useful in the future to identify early OA and patients at risk. The high socioeconomic impact of OA suggests that a better insight into the mechanisms of early OA may be a key to develop more targeted reconstructive therapies at this first stage of the disease. Systematic review, Level II.

Numerical Simulation Analysis of Influence Factors to Shearing Force of Rolling Shear

The calculation results show that relative cut-in depth at the moment of maximum shearing force decreases with the increase of steel plate thickness; along with blade clearance increasing, shearing force would increase slightly compared with the slide pressure of blade carrier; shearing force increases significantly with the increasing blunt end radius; shearing force displays a bit decrement with the decreasing platen force, while the pressure on slide plate of blade carrier increases substantially; shearing force increases a bit with the increasing shear velocity and decreases when nip angle increases while the horizontal component force of shearing force along the direction of plate width increases rapidly. The above results have important reference and actual using value for studying calculation of mechanical parameters of rolling shear and its structural design.

SU‐E‐T‐329: Degrading Electron Beam Energy in Rotational Total Skin Electron Therapy

Purpose: In rotational total skin electron therapy (RTSET), degraded electron beam energy may be required for patient treatment. A method is developed by inserting an acrylic plate in TBIe‐tray to deliver a lower energy beam. The change in percentage depth dose (PDD) verses thickness of plate is studied. Methods: A Rando phantom is used on a rotational platform at an extended SSD (=332 cm) with a linac gantry angled at 90°. A special mode with a TBIe‐insert delivers a 6 MeV electron beam on a Varian 21EX. An acrylic plate is inserted in the TBIe‐tray to degrade 6 MeV electron beam energy. Three different thickness of acrylic plates are 4, 6, and 10 mm. For PDD measurements, Kodak EDR films are sandwiched in the Rando phantom slides. The film surface is oriented parallel to the incident electron beam. The films are analyzed using the RIT113 dosimetry software with a Vidar‐VXR 16 Pro Scanner. Results: Several physical parameters dmax, R50, and Rp are determined in the PDD curves. These parameters vary with the inserted plate thickness. The dmax is around 0.4 cm without acrylic plate (t = 0) and decreases as the plate thickness increases. For 10 mm plate thickness, dmax shifts to the surface of the phantom. The mean energy E0 at the phantom surface can be obtained from R50 for each degraded electron beam using the relationship between Eo and R50. The E0 decreases as the plate thickness increases, indicating 6 MeV electron beam degraded to a lower energy beam. Conclusions: The method to degrade electron beam energy in RTSET offers advantages of easy setup and manageable beam energy than spoiler technique. Most of the treatment parameters can be readily obtained from the PDD data for each degraded electron beam.

Effect of Plate Thickness and Weld Position on Distortion and Residual Stress of Welded Structural Steel

Residual stresses are generated as a result of non-uniform temperature distribution during welding and particularly cooling process during fabrication of the welded parts. Residual stresses have a major effect on the overall performance of a component in service. In this instant, the residual stress in the form of angular distortion is primarily caused by shrinkage on longitudinal and transversal direction. Several single v-butt joints on structural steel plates of SS400 are investigated by using different plate thickness and welding positions (1G and 3G). GMAW method was used in the welding process. Measurement of residual stress was carried out on a plate with the thickness of 16 mm on longitudinal, transversal and normal direction by using neutron diffraction method. Results showed that the angular distortion of the welded plates increase with the increase of plate thickness. Welding by vertical position (3G position) resulted in a bigger angular distortion compared to flat position (1G position). The distribution of residual stress varied between tension and compression residual stress along welded area with the range of -10 mm to 10 mm. Measurement of residual stress on the longitudinal direction has the greatest value among two other directions.

Transmitted and reflected coefficients for horizontal or vertical plate type breakwater

Surface or submerged horizontal or vertical plate can be considered as a new concept breakwater. This paper investigates the wave-plate interaction of this type of breakwater by use of the boundary element method. The relationships of wave transmitted and reflected among plate thickness, submergence and length are carefully studied by numerical simulation. It is shown that: (1) The transmitted coefficients of submerged horizontal plate or vertical plate will become larger with the increase of plate thickness and reduce rapidly with the decrease of plate submergence. (2) Both surface horizontal and vertical plate are efficient for intermediate and short wave elimination, but vertical plate is more effective. (3) Submerged horizontal plate can act more effectively than submerged vertical plate does. With all wave frequencies, the vertical plate almost has no wave elimination effect.

Strength Prediction of Bonded T-Peel Joint with Single Overlap Support

Bonded structure are commonly three types, purely adhesive bonded, weld-bonded and adhesive/mechanical structures. Generally, peel and overlapped joints are commonly used in the development of bonded structures. T-Peel bonded joint has week tensile loading strength compare to double-overlap bonded joint. The present work aimed to predicting the strength of bonded T-peel joint with single overlap support using finite-element method. For comparison purposes, normal bonded T-peel joint is included in this study. It was found the introduction of a single overlap support for bonded T-peel joint strengthening the joint by 300%. Furthermore, it was reported that the proposed joint strength increased further with increase of the overlap support plate length and thickness.

Crutch Weightbearing on Comminuted Humeral Shaft Fractures: A Biomechanical Comparison of Large versus Small Fragment Fixation for Humeral Shaft Fractures

This study evaluated the failure properties of length unstable humerii secured with small or large fragment plates. Two nonlocking plate constructs were examined, a nine-hole 4.5-mm limited contact dynamic compression plate (large fragment group) and a 12-hole 3.5-mm limited contact dynamic compression plate (small fragment group), both on composite humerii with a 1-cm defect to simulate comminution (n = 12 for each group). Each plate construct had similar working lengths and number of fixation points. Mechanical testing was first randomized for stiffness measurements in axial and torsional loads. All constructs were then tested in cyclic axial loads to failure. For axial testing, the large fragment group had a mean stiffness of 1020 ± 195 N/mm compared with 268 ± 67 N/mm in the small fragment group (P < 0.0001). For torsional testing, the large fragment group had a mean stiffness of 1.5 ± 0.05 Nm/degree compared with 0.9 ± 0.04 Nm/degree in the small fragment group (P < 0.0001). Plastic deformation in the large fragment and small fragment groups were 0.09 ± 0.07 mm and 0.20 ± 0.24 mm, respectively (P = 0.1) assessed during cyclic testing up to 300 N. The postcyclic yield force in the large fragment group was 227 ± 30 N and in the small fragment group was 153 ± 5 N (P < 0.0001). The ultimate load in the large fragment and small fragment groups were 800 ± 87 N and 307 ± 15 N, respectively. The results corroborate anticipated plate mechanical behavior with plate stiffness increasing as both plate width and thickness increase. The calculated yield force data suggest that both small and large fragment constructs would experience plastic deformation during bilateral crutch ambulation in a patient weighing 50 kg or more. The large fragment construct is not expected to catastrophically fail when subjected to loads in a patient 90 kg or less. The small fragment construct is predicted to catastrophically fail in patients weighing 70 kg or more.