Rolling Plane Research Articles

The Vibration of Partially Filled Cylindrical Tank Subjected to Variable Acceleration

In this study, the vibration of a cylindrical tank partially filled with liquid under motion modeled as mass lumped is investigated. A three-dimensional quasi-static model of a partially-filled tank of circular cross-section is developed and integrated into a comprehensive three-dimensional vehicle model to study its dynamic performance as a function of acceleration, and the fill volume. The liquid load movement occurring in the roll and pitch planes of the tank is derived as a function of the longitudinal acceleration, and then the corresponding shifted load is expressed in terms of center of mass coordinates and mass moments of inertia of the liquid bulk, assuming negligible influence of fundamental slosh frequency and viscous effects. The vibration characteristics of the partially filled tank vehicle are evaluated in terms of load shift, forces and moments induced by the cargo movement, and dynamic load transfer in the longitudinal direction. The semi analytical response is obtained by means of SimuLink? Matlab Software. The effects of longitudinal acceleration of the tank system on the liquid surface inclination and consequently shifting of centroids and moment of inertia are illustrated.

Effects of Cold Working Ratio and Stress Intensity Factor on Intergranular Stress Corrosion Cracking Susceptibility of Non-Sensitized Austenitic Stainless Steels in Simulated BWR and PWR Primary Water

To evaluate the effects of cold working ratio, stress intensity factor and water chemistry on an IGSCC susceptibility of non-sensitized austenitic stainless steel, constant displacement DCB specimens were applied to SCC tests in simulated BWR and PWR primary water for the three types of austenitic stainless steels, Types 316L, 347 and 321. IGSCC was observed on the test specimens in simulated BWR and PWR primary water. The observed IGSCC was categorized into the following two types. The one is that the IGSCC observed on the same plane of the pre-fatigue crack plane, and the other is that the IGSCC observed on a plane perpendicular to the pre-fatigue crack plane. The later IGSCC fractured plane is parallel to the rolling plane of a cold rolled material. Two types of IGSCC fractured planes were changed according to the combination of the testing conditions (cold working ratio, stress intensity factor and simulated water). It seems to suggest that the most susceptible plane due to fabrication process of materials might play a significant role of IGSCC for non-sensitized cold worked austenitic stainless steels, especially, in simulated PWR primary water. Based upon evaluating on the reference crack growth rate (R-CGR) of the test specimens, the R-CGR seems to be mainly affected by cold working ratio. In case of simulated PWR primary water, it seems that the effect of metallurgical aspects dominates IGSCC susceptibility.

GS14 圧延金属材料の破壊強度異方性に関する研究

Rolled metallic materials have anisotropy of mechanical properties due to the shape of the crystal grain. We have carried out experimental studies focusing on the fracture strength anisotropy of rolled metallic materials. This paper reported anisotropy of fracture toughness of two kinds of rolled steels (SM490A and SS400). SM490A steel shows a property of ductile fracture in the fracture toughness test. On the other hand, SS400 shows a property of brittle fracture. Six kinds of different compact tension specimens of the crack plane orientation were made by these materials. The fracture toughness tests were carried out by these specimens and the fracture toughness values were evaluated. As a result SM490A showed anisotropy clearly. In addition, the fracture surface was different in each direction. The direction relations of rolled plane and crack plane influenced a fracture toughness value. SS400 showed anisotropy, but the tendency was different from that of SM490A. The anisotropy of this material cannot be explained by the relation of two planes.

Victim Fragmentation Patterns and Seat Location Supplements Crash Data: American Airlines Flight 587

In 2001, American Airlines flight 587 crashed shortly after takeoff. All 260 people aboard and 5 people on the ground were killed. This study's objective was to explore the extent of victim injuries and fragmentation patterns along with their assumed seat locations as related to the crash event and the plane's structural damage. There were 2058 body fragments recovered and, of those, 1750 have been identified. Autopsy reports detailing injuries and extent of fragmentation, flight manifest, and the NTSB Aircraft Accident Report were examined for correlations among injuries, seat location, and crash event. Using the AIS as a model, a fragmentation scale was designed to record injury location and severity, with a focus on the extremities. More whole bodies were recovered from victims seated on the plane's right side and back half. Conversely, significantly more fragments for victims seated on the plane's left side were recovered. The increased fragmentation from victims on the left side is an irregular pattern, particularly because the last information from the flight data recorder showed the plane's sideslip to the right. However, there are no data for the flight's final 13.6 s. Most eyewitnesses recount the plane rolling left before crashing. The increased fragmentation of victims seated on the left is consistent with structural damage from a left side impact, corroborating eyewitness accounts. Correlating victim injuries and fragmentation patterns, seat location, and the plane's structural damage can assist an investigation into plane crashes, particularly if flight data are missing.

Crystallographic Texture as a Factor Enabling Ductile Fracture Arrest in High Strength Pipeline Steel

Low ductile crack arrestability in a full-scale burst test of 1420 mm-diameter X80 steel line pipes was accompanied by a high intensity of fracture surface separation. The texture of the steel plates was studied using different techniques in order to evaluate the influence of {001} planes oriented parallel to the rolling plane on the separation intensity during fracture. Though no clear correlation between the content of {001} planes parallel to the rolling plane and intensity of separation was found, the local distribution of the {001}<110> texture component among the microstructure components was different in different steels providing long areas suitable for cleavage fracture parallel to the rolling plane in steel with low arrestability.

Variation of texture parameters in treatment of strip of aluminum and copper alloys and relationship between texture parameters and physical properties

Texture parameters that have been proposed for control of the mechanical properties and ductility anisotropy of sheet face-centered cubic alloys, their variation in the course of manufacture, and relationship to the quality characteristics are investigated. The efficiency of active control in an on-line regime with continuous heat treatment of the alloys to bring the alloys to a state of incomplete primary recrystallization which will alters the texture of the rolled product accompanied by the formation of different orientations with the plane {100} in the rolling plane, in particular, cubic orientations, is determined. Astrategy for the use of active texture control is developed and the limits of its effective application are defined.

Vestibular perceptual thresholds to angular rotation in acute unilateral vestibular paresis and with galvanic stimulation

Studies of compensation of injury to the human vestibular system have, in the main, focused on the vestibular-ocular reflex. Probing vestibular perception allows more of the sensory pathway to be assessed. We present a novel paradigm for simultaneously testing vestibular perceptual and nystagmic thresholds to angular acceleration around an earth vertical axis. The perceptual thresholds can be modulated asymmetrically in normal subjects by DC galvanic stimulation with the head flexed in the roll plane, as expected from the main torsional plane of action of the galvanic stimulus. The perceptual and nystagmic thresholds were bilaterally elevated in acute vestibular neuritis, a unilateral condition, possibly due to central suppression of vestibular input. The degree of asymmetry in thresholds was small in comparison with the large caloric asymmetry present in the patients, indicating a relatively preserved capacity for near-threshold performance of the non-damaged labyrinth both in the "on" and "off" directions.

On the role of crystallographic texture in mitigating hydrogen-induced cracking in pipeline steels

Cathodic hydrogen charging was applied to low-carbon pipeline-steel samples produced using different thermomechanical paths. The samples developed similar microstructures but different crystallographic textures and grain–boundary distributions. This made it possible to investigate the resistance to hydrogen-induced cracking (HIC) of steels with strong {1 1 1}ND and {1 1 2}ND texture fibres, steels with a dominating {0 0 1}ND texture fibre, and steels with close-to-random textures; { h k l}ND representing grain orientations with { h k l} planes parallel to the steel rolling plane. The results show that strong {1 1 1}ND fibre textures produced by warm-rolling schedules significantly increase HIC-resistance of pipeline steels, whereas {0 0 1}ND and close-to-random textures make steels HIC-prone.

Investigation of active vibration control system for trailed two-wheeled implements

This paper presents an active vibration control (AVC) system for trailed two-wheeled implements (TTWI) equipped with high precision electronic devices. With the aim of isolating disturbance forces to the devices, a hydraulically actuated vibration control system is devised. In order to suppress vibratory motions to the body components, considering the TTWI system characteristics, a vibration control and a force tracking control strategy is adopted. As the vibration controller, the adaptive and skyhook control schemes are applied. From full order and reduced order model for the actuating module, as the tracking controller, the sliding mode control scheme is adopted regarding parameter variations. On the basis of the roll plane TTWI system model, simulation work is performed. Finally, after implementation of the experimental setup with the TTWI system and the road simulating module considering practical requirements, actual performance of the devised AVC system is evaluated in various disturbance conditions.

Microstructure and Tensile Properties of Ultrafine Grained Pure Al Sheets Produced by Accumulative Roll Bonding

Usually the heat treatment in the cyclic ARB passes is indispensable to reduce work-hardening effects and improve interface bonding quality. The possibility of accelerating grain refinement of aluminum sheets with a dimension of 300 mm×50 mm×1 mm is investigated during the ARB process at room temperature, in which the samples are rotated by 180 degree around normal plane axis perpendicular to the rolling plane between the adjacent cycles. By means of optical microscopy and transmission electron microscopy, it shows that the bonding interfaces can not obviously observed after five cycles, and grains are refined to be ~0.5 μm. Tensile tests show the ARB samples exhibit strain hardening behavior after yielding without a sudden fracture even up to seven cycles of ARB. The softening behavior and enhanced ductility was explained by dynamic recovery, the recrystallization process and even abnormal large grains.

Quick phases control ocular torsion during smooth pursuit

One of the open questions in oculomotor control of visually guided eye movements is whether it is possible to smoothly track a target along a curvilinear path across the visual field without changing the torsional stance of the eye. We show in an experimental study of three-dimensional eye movements in subhuman primates (Macaca mulatta) that although the pursuit system is able to smoothly change the orbital orientation of the eye's rotation axis, the smooth ocular motion was interrupted every few hundred milliseconds by a small quick phase with amplitude <1.5° while the animal tracked a target along a circle or ellipse. Specifically, during circular pursuit of targets moving at different angular eccentricities (5°, 10°, and 15°) relative to straight ahead at spatial frequencies of 0.067 and 0.1 Hz, the torsional amplitude of the intervening quick phases was typically around 1° or smaller and changed direction for clockwise vs. counterclockwise tracking. Reverse computations of the eye rotation based on the recorded angular eye velocity showed that the quick phases facilitate the overall control of ocular orientation in the roll plane, thereby minimizing torsional disturbances of the visual field. On the basis of a detailed kinematic analysis, we suggest that quick phases during curvilinear smooth tracking serve to minimize deviations from Donders' law, which are inevitable due to the spherical configuration space of smooth eye movements.

A New Device to Quantify Ocular Counterroll Using Retinal Afterimages

Background: The integrity of vertical semicircular canal and otolith function remains difficult to assess in the clinical setting, partly due to difficulties in recording ocular counterroll. Here, we quantify static ocular counterroll from head tilt using a new head-mounted device. Methods: The device consists of an LED positioned 42 cm in front of one eye and a striated lens which produces a streak of light on the retina. The LED is illuminated at full intensity (80 cd) to generate a retinal afterimage. Subsequently, in darkness, the subject’s head is tilted in the roll plane. Finally, the LED is illuminated dimly (0.2 cd) and the subject rotates the striated lens to superimpose the dim light streak onto the afterimage. An angular scale indicates the angle through which the lens is rotated, giving a measure of the ocular counterroll. To validate the device, we recorded binocular counterroll simultaneously with 3D computerised video-oculography of the other eye in 16 normal subjects; 2 patients with acquired bilateral loss of vestibular function were also tested. Results: In the normal subjects, there was no significant difference between the two techniques (p = 0.24) when recording ocular counterroll and the correlation between the two techniques was R² = 0.78. The 2 avestibular patients essentially showed no ocular counterroll with both techniques. Conclusions: We have devised a non-invasive, quick and reliable test of ocular counterroll. The lack of response in the 2 avestibular patients indicates that this device is clinically applicable to assess otolith function.

The linear thermal expansion of bulk nanocrystalline Al and SS304 at low temperature

The linear thermal expansions (LTE) of bulk nanocrystalline (NC) Al, 304 stainless steel (SS304) and their conventional coarse-grained poly-crystalline counterparts (CCPC) were studied by the strain gage method in four directions within rolling plane (for bulk NC SS304 and Al) and one direction (for their CCPC) from liquid nitrogen temperature to 300 K. LTE of bulk NC Al and SS304 in four directions were equal to or less than those of their CCPC. This result was different from the fact that the smaller thermal expansions of many other bulk nanocrystalline materials were larger than those of their CCPC. We had to conclude that the less linear thermal expansions of bulk NC SS304 and Al were attributed to their larger defects at grain boundaries and residual strain. However, the larger linear thermal expansions of many other NC materials resulted from two factors.

Comparison of Two Different Rolling Processes on Microstructure and Properties of Ferrite-Bainite Dual-Phase Pipeline Steels

The microstructure and mechanical properties of ferrite-bainite dual-phase pipeline steels respectively produced by thermomechanical control process (TMCP) and intercritical annealing were studied using optical microscope, scanning electron microscope (SEM), Vickers hardness tester and MTS 810 servo-hydraulic machine. The results show that these two processes obtain different morphology and distribution of microstructure, but the mechanical properties of them are similar and superior, especially the yield ratios are low. It is found that for TMCP steel, the grains of ferrite are large and the average ferrite grain size is approximately 6.1µm. The bainite structures are lump-shaped with concentrated distribution in the ferrite matrix and the band structure is obvious. For steels produced by intercritical annealing process, the grains are finer and the distribution of bainite is uniform on the ferrite grain boundaries. From the rolling plane to the centre, the grain sizes of ferrite in these two microstructures increase obviously, and the volume fraction of bainite first increases significantly, then decreases slightly in the TMCP steel and the average volume fraction is approximately 60.1%. However, the bainite volume fraction in the intercritical annealing steel decreases gradually and the average volume fraction is approximately 35.4%. Moreover, hardness values in through-thickness direction are uniform in the TMCP steel and these values are also similar in the intercritical annealing steel except the values in the region near the rolling plane are much larger.

Antihysteresis of perceived longitudinal body axis during continuous quasi-static whole-body rotation in the earth-vertical roll plane

Estimation of subjective whole-body tilt in stationary roll positions after rapid rotations shows hysteresis. We asked whether this phenomenon is also present during continuous quasi-static whole-body rotation and whether gravitational cues are a major contributing factor. Using a motorized turntable, 8 healthy subjects were rotated continuously about the earth-horizontal naso-occipital axis (earth-vertical roll plane) and the earth-vertical naso-occipital axis (earth-horizontal roll plane). In both planes, three full constant velocity rotations (2°/s) were completed in clockwise and counterclockwise directions (acceleration = 0.05°/s(2), velocity plateau reached after 40 s). Subjects adjusted a visual line along the perceived longitudinal body axis (pLBA) every 2 s. pLBA deviation from the longitudinal body axis was plotted as a function of whole-body roll position, and a sine function was fitted. At identical whole-body earth-vertical roll plane positions, pLBA differed depending on whether the position was reached by a rotation from upright or by passing through upside down. After the first 360° rotation, pLBA at upright whole-body position deviated significantly in the direction of rotation relative to pLBA prior to rotation initiation. This deviation remained unchanged after subsequent full rotations. In contrast, earth-horizontal roll plane rotations resulted in similar pLBA before and after each rotation cycle. We conclude that the deviation of pLBA in the direction of rotation during quasi-static earth-vertical roll plane rotations reflects static antihysteresis and might be a consequence of the known static hysteresis of ocular counterroll: a visual line that is perceived that earth-vertical is expected to be antihysteretic, if ocular torsion is hysteretic.

Correlation Between Microstructure and Texture Development in a Cold-rolled TWIP Steel

X-ray diffraction and optical microscopy were used to characterize the crystallographic texture and the grain microstructure in cold-rolled Fe–23.2Mn–0.57C alloy. The development of texture and microstructure with increasing strain was systematically analyzed. From 10 to 85% rolling reduction the observed microstructure changes can be characterized by four distinctly different features: twin-matrix lamellae, alignment of twins with rolling plane, herring bone structure and macro shear bands. The effect of microstructural heterogeneity on texture was addressed. The observed change of the Cu texture component {112} with increasing strain was attributed to the competition of homogeneous dislocation slip and deformation twinning. The shift of the Brass component towards the Goss orientation at higher reduction levels (> 60%) corresponds to the appearance of a large amount of the shear bands and the formation of the // ND fiber texture – to the alignment of twin-matrix lamellae with rolling plane.

Effect of Severe Cold-Rolling and Subsequent Annealing on Microstructure and Properties of &lt;i&gt;in-Situ&lt;/i&gt; Composite Steel

In this paper, the process of severe cold-rolling and annealing for Q235 steel with lath martensite has demonstrated a new promising technique for producing in-situ composite multi-nanolayer steel. Cold rolling and subsequent annealing have great impact on microstructure evolution as well as mechanical properties. In the as-rolled state, the strength (b 2112 MPa) is approximately four times increased than as-received material, which is attributed to work hardening and grain refining during cold rolling. As cold-rolled sample subjected to further annealing below 500 °C, deformed microstructure underwent further recovery and recrystallization and finally became refined equiaxed grains; ultrafine ferrite grains, nano-carbides precipitated uniformly were seen in the specimen annealed at 500 °C, and the phenomenon of fracture delamination was observed from the specimens, the delamination plane was parallel to the rolling plane, in-situ composite weak interfaces effect has great impact on the fracture surface. Annealing at and above 600 °C resulted in coarse ferrite grains with spheroidized coarse carbides, causing grain growth.

Microstructure Characteristics and Mechanical Properties of &lt;i&gt;in-Situ&lt;/i&gt; Composite Steel Processed by Severe Cold-Rolling and Subsequent Annealing

In this paper, Q235 steel was investigated in order to manufacturing ultra-high strength material. The process of severe cold-rolling and low temperature annealing of lath martensite effectively reduced the crystal size from about 300 nm to 20 nm, and introduced mass weak interfaces in steel, has been demonstrated a new promising technique for producing in-situ composite multi-nanolayer steel with ultra-high strength (b 2112 MPa). Cold rolling and subsequent annealing have great impact on microstructure evolution as well as material mechanical properties. In the as-rolled state, the strength is approximately four times increased than as-received material (hot-rolled state, b 515 MPa), which is attributed to work hardening and grain refining during cold rolling. As the cold-rolled sample subjected to further annealing below 500 , deformed microstructure underwent further recovery and recrystallization, finally became refined equiaxed grains, microstructure characteristics along rolling direction arrangement was decreased; In addition to ultrafine ferrite grains, nano-carbides precipitated uniformly in the specimen annealed at 500 , total elongation increased to 16%, the corresponding yield strength was 1208MPa, much higher than that of as-received samples. The phenomenon of fracture delamination was observed from the specimens, which were cold-rolled and annealed at 500 , and the delamination plane was parallel to the rolling plane. In-situ composite weak interfaces effect has great impact on the fracture surface.

A Polynomial Chaos-Based Kalman Filter Approach for Parameter Estimation of Mechanical Systems

Mechanical systems operate under parametric and external excitation uncertainties. The polynomial chaos approach has been shown to be more efficient than Monte Carlo for quantifying the effects of such uncertainties on the system response. Many uncertain parameters cannot be measured accurately, especially in real time applications. Information about them is obtained via parameter estimation techniques. Parameter estimation for large systems is a difficult problem, and the solution approaches are computationally expensive. This paper proposes a new computational approach for parameter estimation based on the extended Kalman filter (EKF) and the polynomial chaos theory for parameter estimation. The error covariances needed by EKF are computed from polynomial chaos expansions, and the EKF is used to update the polynomial chaos representation of the uncertain states and the uncertain parameters. The proposed method is applied to a nonlinear four degree of freedom roll plane model of a vehicle, in which an uncertain mass with an uncertain position is added on the roll bar. The main advantages of this method are an accurate representation of uncertainties via polynomial chaos, a computationally efficient update formula based on EKF, and the ability to provide a posteriori probability densities of the estimated parameters. The method is able to deal with non-Gaussian parametric uncertainties. The paper identifies and theoretically explains a possible weakness of the EKF with approximate covariances: numerical errors due to the truncation in the polynomial chaos expansions can accumulate quickly when measurements are taken at a fast sampling rate. To prevent filter divergence, we propose to lower the sampling rate and to take a smoother approach where time-distributed observations are all processed at once. We propose a parameter estimation approach that uses polynomial chaos to propagate uncertainties and estimate error covariances in the EKF framework. Parameter estimates are obtained in the form of polynomial chaos expansion, which carries information about the a posteriori probability density function. The method is illustrated on a roll plane vehicle model.

Effect of cooling rate on transformation texture and variant selection during β → α transformation in Ti–5Ta–1.8Nb alloy

The evolution of texture in a cold rolled Ti–5Ta–1.8Nb alloy sheet, during the α → β → α transformation has been studied using EBSD and XRD techniques, for different cooling rates. The sheet exhibited a basal plane type texture upon cold rolling, and a sharp ‘{1 1 −2 0}||rolling plane’ transformation texture was inherited after the heat treatment. The microtexture analysis of the lamellar α/β structure, suggested that this transformation texture arises from the {1 1 1}〈1 1 0〉 type of high temperature β texture, obeying the Burgers orientation relationship. The strength of the transformation texture was found to sharply increase with decrease in cooling rates, denoting variant selection. Two types of parent β orientations with [1 1 0] parallel to either rolling directions are possible, and among their α product variants, 3 of them are common, and can be preferentially formed at the prior-β grain boundaries. The role of grain boundary-α in influencing variant selection and the transformation texture for different cooling rates is described in this paper.