Horizontal Deflection Research Articles

Synchroscan streak camera imaging at a 15-MeV photoinjector with emittance exchange

At the Fermilab A0 photoinjector facility, bunch-length measurements of the laser micropulse and the e-beam micropulse have been done in the past with a fast single-sweep module of the Hamamatsu C5680 streak camera with an intrinsic shot-to-shot trigger jitter of 10–20ps. We have upgraded the camera system with the synchroscan module tuned to 81.25MHz to provide synchronous summing capability with less than 1.5ps FWHM trigger jitter and a phase-locked delay box to provide phase stability of ∼1ps over 10s of minutes. These steps allowed us to measure both the UV laser pulse train at 263nm and the e-beam via optical transition radiation (OTR). Due to the low electron beam energies and OTR signals, we typically summed over 50 micropulses with 0.25–1nC per micropulse. The phase-locked delay box allowed us to assess chromatic temporal effects and instigated another upgrade to an all-mirror input optics barrel. In addition, we added a slow sweep horizontal deflection plug-in unit to provide dual-sweep capability for the streak camera. We report on a series of measurements made during the commissioning of these upgrades including bunch-length and phase effects using the emittance exchange beamline and simultaneous imaging of a UV drive laser component, OTR, and the 800nm diagnostics laser.

바톰애쉬를 이용한 환경친화적 뒤채움재의 실내모형실험

A small-scale chamber test laboratory for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. Laboratory test which was simulated during contruction stage was conducted. The vertical deflection of 4.43mm to 6.6mm, and the horizontal deflection of 5.49mm to 15.9 mm were measured during backfilling. In case of loading, the vetical deflection of 2.41mm to 8.69mm, and the horizontal deflection of 1.66mm to 2.53mm were measured. Its residual deflections were 1.40mm to 5.93mm for vertical and 1.66mm to 2.53mm for lateral. The vertical and horizontal deflecto of controlled low strength materials were smaller than that of sand backfill. Also, it was same trend for the measured surface settlement.

지중매설 연성관의 관강성 추정

In this paper, we present the result of an investigation pertaining to the pipe stiffness of buried flexible pipes. Pipe stiffness (PS) formula for the parallel plate loading condition is derived based on the elasticity theory. Vertical and horizontal displacements are also derived. Vertical deflection is always larger than the horizontal deflection because some of energy due to overburden load is stored in the pipe but the difference is negligibly small. In the study, mechanical properties of the flexible pipes produced in the domestic manufacturer are tested and the results are reported in this paper. In addition, pipe stiffness is determined by the parallel plate loading tests and the finite element analysis. The difference between test and analysis is less than 14% although there are significant variations in the mechanical properties of the pipe material. Therefore, it was found that the finite element analysis can be used to predict the pipe stiffness instead of conducting parallel plate loading test.

Numerical modelling of installation effects for diaphragm walls in sand

The scopes of this work are to study the mechanisms of load transfer and the deformations of the ground during slurry trenching and concreting in dry sand and to evaluate their effects on service structural loads, wall deflections and ground displacements behind the wall caused by subsequent excavation. A series of three-dimensional finite element analyses was carried out modelling the installation of diaphragm walls consisting of panels of different length. The soil was modelled as either linearly elastic-perfectly plastic or incrementally non-linear (hypoplastic) with elastic strain range. Plane strain analyses of diaphragm walls of identical cross section were also carried out in which wall installation was either modelled or the wall was wished in place (WIP). The analyses predict ground movements consistent with the experimental observations both in magnitude and trend. The results also show that the maximum horizontal wall deflections and structural loads reduce with increasing panel aspect ratio towards a minimum which is about twice the value computed for WIP analyses. Panel aspect ratios should be larger than about three to take advantage of the three-dimensional effects. The pattern and magnitude of surface vertical displacements obtained from linearly elastic-perfectly plastic analyses, no matter whether three- or two-dimensional, are unrealistic.

Periods of Vibration of Braced Frames with Outriggers

This paper presents simple equations for the natural lateral and rotational periods of vibration for high-rise steel structures comprising braced frames with outrigger trusses. The structural floor plan can be symmetric or asymmetric combinations of identical bents. Each braced frame is modelled by a cantilever with a bending stiffness and racking shear stiffness. The outriggers are represented by a rotational spring. The stiffness of the outrigger spring is dependent on three specific modes of behaviour: bending and racking shear in the outrigger truss and axial lengthening or shortening of the exterior columns. This yields a simple calculation of the maximum horizontal deflection of the structure. For the rotational frequencies, the bending, racking shear and spring stiffness parameters of the steel structure each are combined to yield a torsional stiffness, a warping stiffness and a warping spring stiffness which allow an assessment of the rotation at the top. The approximate method of analysis relates the natural frequencies of the structure to the top deflection and rotation when the self-weight is taken as a distributed horizontal load. In the calculations a braced frame is represented by a rigid stick model with its overall flexibility assigned to a rotational spring at the base. Results obtained by the simplified method are compared to those from a finite element analysis. The approximate method gives acceptable conservative results for preliminary analysis.

No direct correlation of mantle flow beneath the North China Craton to the India-Eurasia collision: constraints from new SKS wave splitting measurements

SUMMARY The long-range effects of the ongoing India–Eurasia collision and their role in the Cenozoic tectonic evolution of eastern China are not well understood. Here, we investigate deformation beneath the North China Craton and the Qilian Mountain region between the Haiyuan and Kunlun faults, both of which are located immediately to the northeast of the Tibetan Plateau. We present teleseismic shear wave splitting parameters from 299 broad-band stations. These stations provided good spatial coverage in mapping upper-mantle deformation beneath the North China Craton and the Qilian Mountain. The backazimuth dependence of fast directions fromstationslocatedwithintheQilianMountainregionindicatesacomplexanisotropypattern. A multilayer anisotropy and/or anisotropy with a dipping symmetry axis may exist beneath the Qilian Mountain. The overlapping or underthrusting of material evident in anisotropy from this region may be a long-range effect of the India–Eurasia collision. The central North China Craton showed spatially coherent fast directions and the shear wave velocity anomalies within the upper mantle. These patterns suggest horizontal deflection of a regional mantle upwelling, possibly originating from the mantle transition zone. Anisotropy with large delay times was observed in the vicinity of Shanxi rift system. High ∂lnVS/∂lnVP values for the upper mantle indicate that anisotropy in this area is enhanced by vertically aligned melt-filled fissures. Our results suggest that the dynamic processes beneath the central North China Craton are not directly related to the India–Eurasia collision.

On-chip manipulation of nonmagnetic particles in paramagnetic solutions using embedded permanent magnets

This study develops a method for embedding permanent magnets into poly(dimethylsiloxane) (PDMS)-based microfluidic chips. Magnets can be brought very close to the planar microchannels for enhanced magnetic field and field gradients, which enables on-chip continuous-flow manipulation of nonmagnetic particles in typical paramagnetic solutions. We performed a systematic study of the transport of polystyrene particles suspended in manganese (II) chloride (MnCl2) solutions through a rectangular microchannel. Owing to their smaller magnetization than the suspending fluid, particles experience negative magnetophoresis and are deflected away from the magnet. The effects of particle position (relative to the magnet), particle size, MnCl2 salt concentration, and fluid flow velocity on the horizontal magnetophoretic deflection are examined using a combined experimental and theoretical approach. The experimental results agree quantitatively with the predictions of an analytical model. The demonstrated nonmagnetic particle deflection may be used with the potential to focus and sort cells in lab-on-a-chip for bio-applications.

Use of emperical approaches and numerical analyses in design of buried flexible pipes

In this article, vertical and horizontal deflections in 18 thermoplastics pipes buried under high fills within the scope of Ohio University project were analyzed by using the Iowa equation which is a traditional approach in design of buried flexible pipes, approaches derived from this equation and the method developed by German Standards. During the investigation, the results obtained through these methods were evaluated by taking pipe and backfill material into account. Furthermore, the behavior of thermoplastic pipes and burial medium were 2D modeled and analyzed with finite element method. The results determined through analyses conducted with the finite elements method as well as empirical approaches were compared with field measurements and evaluated. Key words: Flexible pipe, deflection, modified Iowa equation, German method, ATV, PLAXIS analysis.

Limit Load Carrying Capacity of Two-Way Slabs with Two Edges Clamped and Two Edges Simply Supported in Fire

This paper presents test results of temperature distribution, central vertical deflection, and edge horizontal deflection of a two-way concrete slab with two edges clamped and two edges simply supported in fire. On the basis of experimental results, a segment equilibrium method was presented to calculate the limit load-carrying capacity of concrete slabs in fire conditions. The model considered the tensile membrane action contributing to the vertical component of reinforcement tensile forces after the formation of mechanism of the plastic hinge line. The model could clearly predict the effect of the restraint end moment on the plastic hinge line pattern. Comparison between the developed model and test results showed good correlation.

The Research on the Dynamic Response of Arched Corrugated Metal Roof Structure with Ring Hoops

The paper is based on the relatively large-span, thin thickness of the arched corrugated metal roof (ACMR) and the fact that the structure would suffer asymmetry swinging within the vertical plane and structure vibration under the effect of the wind and earthquake. A structure strengthening method called the arched corrugated metal roof with ring hoops (ACMRH) is adopted. With SAP2000, a finite element model is established, with type of w666-18m span, rise-span ratio 0.25, 1mm of thickness and condition of fixed support as its research object. The dynamic time history response is analyzed and compared with documents [1]. Result is shown as below. With the same earthquake wave on the structure added, the vertical and horizontal deflection displacement of the most unfavorable point of the arched corrugated metal roof with ring hoops is always less than that of the structure without ring hoops. The maximal decrement is about 28%. This result indicates the arched corrugated metal roof with ring hoops has a better effect on controlling the displacement deformation.

GOTIC2: A Program for Computation of Oceanic Tidal Loading Effect

Oceanic tidal loading signals are in general smaller than solid Earth tide signals, but they can be measured by geodetic technique and need to be accurately corrected for because they are in general a source of noise. In order to meet this requirement we have developed a program to compute the loading tide most accurately in Japanese region by using a combination of global and regional ocean tide models and fine-scale land-sea grids. The program computes six kinds of loading (radial and horizontal displacements, gravity, tilt, strain, and deflection of the vertical) for 21 constituents including long-period tide.

A comparison of the rigidity of five mandibular major connectors for partial removable dental prostheses via load deflection

The rigidity of the major connector for partial removable dental prostheses (PRDP) has not been well defined. There is little scientific evidence to support specific standards relative to the dimensions of a casting and their effect on long-term function of the PRDP or the supporting tissues. The purpose of this study was to compare in vitro the effects of load deflection of 5 clinically used mandibular major connector forms. A partially edentulous dental cast of a patient with the mandibular anterior teeth remaining was used as the test model. Lingual plate (LP), continuous bar (CB), sublingual bar (SB), lingual bar (LB), and dental lingual bar (DLB) specimens (n=5) were waxed on identical refractory casts, then cast in cobalt base alloy and finished. Each specimen was placed on a custom test table and statically loaded in the contralateral second molar region with 500 g in the horizontal and vertical planes. Deflections were measured at the terminal abutment rest seat, anterior to the load. Comparisons between group means were evaluated using the Dunnett T3 method, assuming unequal variances, for all pairwise tests at a .05 significance level and for 95% confidence intervals for group mean differences. Differences within the groups for vertical versus horizontal deflections were compared using a paired t test and Bonferroni correction (alpha=.05 for all tests). Horizontal deflection between LP and LB, CB and LB, and SB and LB were significant, with the first in each comparison having the least amount of deflection. A significant difference was also seen in the vertical deflection, with the first in each comparison observed to have deflected the least for LP versus CB, LP versus LB, LP versus DLB, CB versus DLB, LB versus DLB, and SB versus DLB. The amount of vertical deflection was significantly greater than the horizontal deflection for all 5 mandibular major connectors (P< or =.033). In the horizontal plane, a significant difference in the amount of deflection was seen between the LP and LB, CB and LB, and LB and SB. In the vertical plane, the LP deflected significantly less than the CB, LB, and DLB. In addition, the DLB deflected significantly more in the vertical plane when compared to the CB, LB, and SB. All 5 mandibular major connectors had a significantly greater amount of vertical deflection as compared to horizontal deflection.

English

Subsonic wind tunnels are generally aerodynamic equipment allowing to obtain in one of their elements, namely in the experimental area where the model is placed, a uniform and stable airflow of determined speed. Wind tunnels of low subsonic speed, usually with continuous running, are plants where the air, driven by a fan, reach in the experimental area speeds up to 180 m/s (M <0,5). They look like tubes with (convergent - divergent) variable section. In our case the wind tunnel is a Prandtl type closed circuit in a horizontal plane, with a single return circuit and closed testing room. To reduce turbulence in the wind tunnel, the number of fan blades whose peripheral speed should not exceed 200 m/s should be as large as possible (which is the case of the INCAS subsonic wind tunnel with 12 blades). The present article is focused on the following topics: vertical and horizontal deflection and turbulence in the experimental area.

Stresses in cast-iron pipes due to seasonal shrink-swell of clay soils

The causes of pipe damage that lead to leakages and bursts in water distribution networks are numerous, and the significance of each possible mechanism is not yet fully understood. This paper reports field monitoring and numerical modelling carried out to evaluate the potential for vegetation-induced desiccation to impose significant bending and therefore additional stress on buried water pipes. Over a period of two years, vertical and horizontal deflections were measured along two flexible pipes buried in London Clay in the vicinity of an oak tree. Meteorological measurements made at the site allowed soil moisture deficit to be computed, and these values were compared with regional values supplied by the UK national meteorological office. Finite difference continuum analyses were carried out in order to permit the interpretation of measured deflections in terms of the equivalent stress increases that would be imposed on a rigid cast iron water pipe. The calculated maximum tensile stress increase was found to be significant in terms of the residual strength of a corroded cast iron pipe.

Effects of overheight truck impacts on intermediate diaphragms in prestressed concrete bridge girders

This paper studies the capacity of prestressed concrete bridge girders to withstand overheight truck impacts. The numerical model of the bridge was validated with the existing experimental data in the literature. The elastic-plastic modeling of concrete damage and quasi-static impact simulation of the bridge were considered. Parametric studies were then conducted with respect to the spacing and depth of intermediate diaphragms as well as girder types from which the role of intermediate diaphragms in protection and enhancement of prestressed concrete bridge girders from truck impacts is obtained. From the simulation results, it was concluded that the optimum spacing of intermediate diaphragms (that is, 25.0 ft [7.62 m]) is consistent with the results reported for previous studies. The depth of intermediate diaphragms should be extended to the top edge of the bottom flange of girders to provide maximum impact protection. Wide flanges in girders increase the bending stiffness and reduce the horizontal deflection and correspondingly decrease damage areas. However, deep webs in girders introduce a large rotation with respect to the deck, and thus increase the deflection under the truck impact. Design guidelines for typical parameters for intermediate diaphragms in prestressed concrete bridges are provided. The numerical finite-element parametric study provides a better understanding of placement and size of intermediate diaphragms in prestressed concrete bridges and their role in protecting girders from overheight truck impacts.

Effects of repeated paleoearthquakes on the Alhama de Murcia Fault (Betic Cordillera, Spain) on the Quaternary evolution of an alluvial fan system

In this work we present a study of an alluvial fan system, which is affected by the Quaternary activity of the leftlateral, reverse Alhama de Murcia Fault (Betic Cordillera). Paleoseismic studies in this area yield data that can be compared and correlated with the morphologic and tectono-sedimentary evolution of the alluvial fan. The spatial arrangement of the sedimentary alluvial fan units near the fault zone, shown in trenches, is controlled by the recurrent reverse, left-lateral coseismic events. We analysed the morphology of the drainage network using a 1:5000 scale orthoimage to identify and measure horizontal deflections along the fault. The channel pattern analysis allowed us to estimate the average horizontal slip rate of the SAMF for the last 130 ka. This value is 0.21 mm/a, which is slightly higher than the range of values obtained by trenching analysis for the last 30 ka, (0.06 to 0.15 mm/yr). The interpretation of the stratigraphic sequence exposed along the trench walls constrained the occurrence of at least two surface faulting earthquakes during the last 30000 years. The most recent event happened after the El Saltador Creek dissected the alluvial fan. The penultimate event occurred while the alluvial fan was still active.

Performances of the scanning system for the CNAO center of oncological hadron therapy

In hadron therapy one of the most advanced methods for beam delivery is the active scanning technique which uses fast scanning magnets to drive a narrow particle beam across the target. The Centro Nazionale di Adroterapia Oncologica (CNAO) will treat tumours with this technique. The CNAO scanning system includes two identical dipole magnets for horizontal and vertical beam deflection, each one connected to a fast power supply. The dose delivery system exploits a set of monitor chambers to measure the fluence and position of the beam and drives the beam during the treatment by controlling the sequence of currents set by the power supplies. A test of the dynamic performance of the scanning system has been performed using a Hall probe to measure the field inside the magnet and the results are presented in this paper.

Air Leakage of Curtain Walls - Diagnostics and Remediation

This article demonstrates how monitoring of construction during a laboratory mock-up test was used to diagnose proneness to air leakage and to devise improved details. The curtain wall was built on a moveable, rigid frame that simulates the load-bearing structure. Construction details and components were identical to those used in actual buildings. The frame brings the curtain wall into contact with the test box, ensuring that the wall’s structural supports are not affected. Construction activities were monitored while the measurements included air flow rate versus air pressure difference across the wall, and horizontal deflections of wall mullions and beams. Locations of leakage points were detected using white smoke. The wall showed a density of air flow rate of 1.5 m3m-2h -1 at a pressure difference of ∼300 Pa, barely meeting the requirements for EN 12152 classification level A2. Correlating leakage points with detected construction weaknesses led to remedial actions by the manufacturer. The tests were repeated, revealing an improved air-tightness (density of air flow rate less than 0.6 m3m- 2h-1 at 350 Pa, and 0.8 m3m -2h-1 when extrapolated to 600 Pa), which meets the requirements for classification level E.

Confocal Examination of Subsurface Cracking in Ceramic Materials

The original ceramic surface finish and its microstructure may have an effect on crack propagation. The purpose of this study was to investigate the relation between crack propagation and ceramic microstructure following cyclic fatigue loading, and to qualitatively evaluate and quantitatively measure the surface and subsurface crack depths of three types of ceramic restorations with different microstructures using a Confocal Laser Scanning Microscope (CLSM) and Scanning Electron Microscope (SEM). Twenty (8 x 4 x 2 mm(3)) blocks of AllCeram (AC), experimental ceramic (EC, IPS e.max Press), and Sensation SL (SSL) were prepared, ten glazed and ten polished of each material. Sixty antagonist enamel specimens were made from the labial surfaces of permanent incisors. The ceramic abraders were attached to a wear machine, so that each enamel specimen presented at 45 degrees to the vertical movement of the abraders, and immersed in artificial saliva. Wear was induced for 80K cycles at 60 cycles/min with a load of 40 N and 2-mm horizontal deflection. The specimens were examined for cracks at baseline, 5K, 10K, 20K, 40K, and 80K cycles. Twenty- to 30-microm deep subsurface cracking appeared in SSL, with 8 to 10 microm in AC, and 7 microm close to the margin of the wear facets in glazed EC after 5K cycles. The EC showed no cracks with increasing wear cycles. Seventy-microm deep subsurface cracks were detected in SSL and 45 microm in AC after 80K cycles. Statistically, there was significant difference among the three materials (p < 0.05). Bonferroni multiple comparison of means test confirmed the ANOVA test and showed that there was no statistical difference (p > 0.05) in crack depth within the same ceramic material with different surface finishes. The ceramic materials with different microstructures showed different patterns of subsurface cracking.

Experimental Study on the Behavior of Full-Scale Composite Steel Frames under Furnace Loading

In current design codes, structural fire behavior is evaluated by conducting experiments on isolated structural elements in a standard fire condition. In such tests involving single isolated elements, many aspects of structural behavior that occur due to the interaction between adjacent members as well as the role of connections cannot be studied. Performance of real structures subject to fires is often much better than that predicted from standard tests due to structural continuity and the interaction between members. In addition, tests performed under the current design codes subject the structural element to a heat up phase only and do not consider the cool-down phase during which local/global failure of the structure may occur. This paper describes the results of a furnace test conducted on two full-scale composite steel frames. In one frame the beam-to-column connections were protected while in the second frame the columns as well as the beam-to-column connections were protected. A special test furnace was built in which full-scale frames could be tested under load. The structural frame was subjected to a heat up phase followed by a cool-down phase. During the test, the furnace temperature, steel and concrete temperatures as well as the horizontal and vertical deflections were recorded. The complete deformation process of the test frame observed during the heating phase and the cooling phase, including failure of the frame is described in this paper. A comparison of the data obtained from the two tests indicates that the fire resistance of a composite beam is significantly better than that of a steel column. Finally, experimental data on fire resistance of composite frames with conventional floor slab construction was compared with data from slim floor slab construction. Results indicate that the fire resistance rating of frames constructed with slim floor slabs is at least as good as that of frames with conventional floor slab construction. It is proposed that in certain engineering design scenarios, the composite beam may not have to be protected due to its higher fire resistance rating, while the steel column should be protected from fire heating.