Beam Wall Research Articles

Octahedral spherical hohlraum and its laser arrangement for inertial fusion

A recent publication [K. Lan et al., Phys. Plasmas 21, 010704 (2014)] proposed a spherical hohlraum with six laser entrance holes of octahedral symmetry at a specific hohlraum-to-capsule radius ratio of 5.14 for inertial fusion study, which has robust high symmetry during the capsule implosion and superiority on low backscatter without supplementary technology. This paper extends the previous one by studying the laser arrangement and constraints of octahedral hohlraum in detail. As a result, it has serious beam crossing at θL≤45°, and θL=50° to 60° is proposed as the optimum candidate range for the golden octahedral hohlraum, here θL is the opening angle that the laser quad beam makes with the Laser Entrance Hole (LEH) normal direction. In addition, the design of the LEH azimuthal angle should avoid laser spot overlapping on hohlraum wall and laser beam transferring outside hohlraum from a neighbor LEH. The octahedral hohlraums are flexible and can be applicable to diverse inertial fusion drive approaches. This paper also applies the octahedral hohlraum to the recent proposed hybrid indirect-direct drive approach.

直流光阴极注入器电子束壁损失初步研究

直流光阴极注入器电子束壁损失初步研究

19C 필리핀 세부(Cebu) 바하이 나 바토(bahay na bato) 주택의 기후적 인자를 고려한 공간 구성에 관한 연구

The modern town houses in Philippines has been changed through Spanish colonization over 300years and American military administration in 20C. Especially Cebu, the first contemporary capital of colonized Philippines by Spain, has various cultural characteristics and historical remains including old houses. By the economy condition in Cebu growing up, Bahay na bato, stone and wood house, has been settled for the elite or middle class of Cebu around 19C influenced by Spanish or Europe and Philippines native house called bahay kubo. Bahay na bato shows a common features, as revealed in this study, which all of them has a two stories with cut stone curtain wall and wooden beam and lintel, fronting the main street by approaching directly from street. And spatial separating also shown by setting living space to upper level instead of using storage or entrance hall called zaguan in lower level. Bahay na bato studied here shows a particular appearances in elevation, having volada and elaborate geometric or floral window pattern, also playing a role for ventilation with vetanilas below volada and main window in section. They have a rectangular plan with caida, sala, comedo, azotea almost similar to Spanish and ealier colonial Mexico style mixed with Philippines traditional style showing the strong spatial separation functionally and space wideness for party occasionally.

Beam Frame Supported Shear Wall Structure Based on the ANSYS Finite Element Static Analysis of Beam-Type Transfer Floor

This article research frame supported shear wall structure Beam-type Transfer layer at the supporting wall (across full) shape and the supporting column two structure forms, in the same form of vertical uniformly distributed load, the stress distribution variation trend and characteristics of the analyzed and discussed. Using large-scale finite element analysis software ANSYS to two different Beam-type Transfer structure of the nonlinear simulation analysis, combined with the stress nephogram of X to the analysis of two kinds of structure forms of the transfer beam and upper wall and the frame work characteristics [. The results of the study show that: In terms of the vertical stress, wall shape across the full shear wall in the stress of the beam structure performance is better, Column will produce large stress in the beam. Shear wall and stress of the transfer beam work together to transform beam has a great influence.

Stiffness and Energy Dissipation of Steel Coupling Beam Embedded in the PSH2C and Normal Concrete Shear Wall

Hybrid coupled shear wall with steel coupling beams has often been used as load-resisting system of high-rise buildings under lateral loads. However, joint between steel beam and shear wall is under combined and high stress. Reinforcement details of the joint are very heavy. This study addresses the effect of shear wall cement composites type in hybrid wall system on the seismic performance of steel coupling beams embedded in shear wall. The main test variables were the failure mode of steel coupling beam and types of cement composites, such as PSH2C and concrete, for shear wall.

SU-E-T-82: Change of Ionization Chamber Correction Factors (Ppol , Pion , KWall ) with Chamber Walls of Different Materials in Continuous and Pulsed Beams

Purpose: To study the effect of wall material on correction factors for polarity effect Ppol , collection efficiency Pion and scatter and attenuation in the chamber wall/central electrode Kwall , in continuous and pulsed beams. Methods: An Exadin A12 ionization chamber was modified to have geometrically identical chamber walls built from aluminum and copper. Measurements were performed using the different walls in both 60Co, and Varian‐Clinac 21EX 6 MV beams. Ppol was measured using AAPM TG51 protocol. Pion was obtained form measurement data, where the collected charge was measured at 10 voltage settings and used to form Jaffe‐plots. Measurements were compared against Monte Carlo simulated data (egs++/egs_chamber). Kwall values were also calculated using CAVRZnrc. Results: For all beams and all wall materials, Ppol was found to be less than the 0.3 % limit recommended in TG‐51. Saturation charges (extrapolated from the Jaffe‐plots) were observed to increase with wall materials of increasing atomic number Z. The breakdown of the Boag‐predicted linearity of Jaffe‐plots in the near‐saturation region was observed for all beam types and wall materials. The ratio of the saturation charges (relative to the C552 wall) were predicted by cavity theory, and agreed with simulations to within 9.8 % for 60Co and 5.2 % for 6 MV. Pion measured by the two‐voltage technique and from Jaffe‐plots were all found to be less than the 1.05 accepted upper limit recommended by TG‐51. Kwall showed that attenuation and scatter for the Cu wall influences the measured signal by 1.9 % for 60Co. Conclusion: Ppol and Pion were measured for an Exradin A12 chamber with C552, Al, and Cu wall materials. The basic behavior of Jaffe‐plots is independent of wall material. As expected, Kwall increases drastically for high Z walls with decreasing beam energies.

An extremum method for bending-wrinkling predictions of inflated conical cantilever beam

An extremum method is presented to predict the wrinkling characteristics of the inflated cone in bending. The wrinkling factor is firstly defined so as to obtain the wrinkling condition. The initial wrinkling location is then determined by searching the maximum of the wrinkling factor. The critical wrinkling load is finally obtained by determining the ratio of the wrinkling moment versus the initial wrinkling location. The extremum method is proposed based on the assumption of membrane material of beam wall, and it is extended to consider beam wall with thin-shell material in the end. The nondimensional analyses show that the initial wrinkling location is closely related to the taper ratio. When the taper ratio is higher than the critical value, the initial wrinkles will be initiated at a different location. The nondimensional critical wrinkling load nonlinearly increases as the taper ratio increases firstly, and then linearly increases after the critical taper ratio. The critical taper ratio reflects the highest load-carrying efficiency of the inflated cone in bending, and it can be regarded as a measure to optimize the geometry of the inflated cone. The comparative analysis shows fairly good agreement between analytical and numerical results. Over the whole range of the comparison, the mean differences are lower than 3%. This gives confidence to use extremum method for bending-wrinkling analysis of inflated conical cantilever beam.

Helicon thruster plasma modeling: Two-dimensional fluid-dynamics and propulsive performances

An axisymmetric macroscopic model of the magnetized plasma flow inside the helicon thruster chamber is derived, assuming that the power absorbed from the helicon antenna emission is known. Ionization, confinement, subsonic flows, and production efficiency are discussed in terms of design and operation parameters. Analytical solutions and simple scaling laws for ideal plasma conditions are obtained. The chamber model is then matched with a model of the external magnetic nozzle in order to characterize the whole plasma flow and assess thruster performances. Thermal, electric, and magnetic contributions to thrust are evaluated. The energy balance provides the power conversion between ions and electrons in chamber and nozzle, and the power distribution among beam power, ionization losses, and wall losses. Thruster efficiency is assessed, and the main causes of inefficiency are identified. The thermodynamic behavior of the collisionless electron population in the nozzle is acknowledged to be poorly known and crucial for a complete plasma expansion and good thrust efficiency.

Contamination Analysis of Radioactive Samples in Focused Ion Beam Instruments

The use of Focused Ion Beam (FIB) instrument's to analyze and prepare samples that are radioactive requires attentiveness to the materials that are dislodged and free inside the chamber. Radioactive sputtered material must be understood even when observed at trace concentrations. Measurements using liquid scintillation counting and high purity germanium detectors were used to evaluate contamination on accessible surfaces inside a focused ion beam chamber that was used in the preparation of samples that were radioactive. The maximum removable contamination found was 0.27 0.4 Bq cm(-2), on the focused ion beam wall with 0.24 0.019 Bq cm(-2) on the door. Although these magnitudes of removable contamination are inconsequential for activation products, these same magnitudes of actinides, for example 239Pu, would represent 3.2% of an Annual Limit of Intake. This might be considered significant if one examines the relatively infrequent use of this device for the preparation of radioactive samples. Predicted activities of sputtered material were found using the software Transport of Ions in Matter, estimating that 0.003% of a radioactive samples activity is released into the FIB chamber. A used secondary electron detector's activity was measured to be 383.7 8.1 Bq. Preferential build-up of sputtered materials due to temperature or static charge gradients was considered. No temperature gradients were observed. Static charge gradients were measured inside the chamber varying between 0.057% below the mean to 34% higher than the mean. However, the magnitudes of contamination measured did not correlate to static charge gradients. Deposition in the chamber appears to have no mechanical cause but rather is sporadic however, measureable. Experience to date has been limited to samples of low activity; nevertheless, contamination inside the chamber was observed. Users should anticipate higher levels of readily dispersible radioactive contamination within the FIB as sample activity increases.

Bending Moment Calculations for Piles Based on the Finite Element Method

Using the finite element analysis program ABAQUS, a series of calculations on a cantilever beam, pile, and sheet pile wall were made to investigate the bending moment computational methods. The analyses demonstrated that the shear locking is not significant for the passive pile embedded in soil. Therefore, higher-order elements are not always necessary in the computation. The number of grids across the pile section is important for bending moment calculated with stress and less significant for that calculated with displacement. Although computing bending moment with displacement requires fewer grid numbers across the pile section, it sometimes results in variation of the results. For displacement calculation, a pile row can be suitably represented by an equivalent sheet pile wall, whereas the resulting bending moments may be different. Calculated results of bending moment may differ greatly with different grid partitions and computational methods. Therefore, a comparison of results is necessary when performing the analysis.

Performance Experiment Study of the Embedded Anchor of the Concrete Wall and Steel Beam Connection

Performance Experiment Study of the Embedded Anchor of the Concrete Wall and Steel Beam Connection

Optimization of Casing Wall Structure of Electrostatic Precipitator - A Case Study

The conventional structural design of wallboard of electrostatic precipitator casing uses the wall structure of stiffened flat sheet which consumes a great amount of steel. Consequently, a new structural idea was explored to optimize the conventional design which applied profiled steel sheet and located wall beam and wall column. The codes were written which designed and analyzed the wall structure of casing. On the basis of a practical project, as the design parameters were varying, the codes were used to automatically compute the strength, stability, stiffness and steel consumption of profiled steel sheet, wall beam and wall column of the corresponding design case. Then, the design with the minimum steel consumption was selected as the optimum one among all the cases which could satisfy the design requirements. The characteristics of the optimum section shape were generalized. The influence of structure layout on the minimum total steel consumption of casing wall structure was investigated. The total steel consumption of casing wall structure is comparatively small when wall column and wall beam divide the whole wallboard into several smaller blocks whose aspect ratio is about 1.6-2.9. Compared with the original wall structure of stiffened steel sheet, the optimized wall structure composed of profiled sheet, wall column and wall beam can save steel significantly which can be applied widely in large-scale electrostatic precipitator casing structures.

An elastic-plastic analysis of short-leg shear wall structures during earthquakes

Short-leg shear wall structures are a new form of building structure that combine the merits of both frame and shear wall structures. Its architectural features, structure bearing and engineering cost are reasonable. To analyze the elastic-plastic response of a short-leg shear wall structure during an earthquake, this study modified the multiple-vertical-rod element model of the shear wall, considered the shear lag effect and proposed a multiple-vertical-rod element coupling beam model with a new local stiffness domain. Based on the principle of minimum potential energy and the variational principle, the stiffness matrixes of a short-leg shear wall and a coupling beam are derived in this study. Furthermore, the bending shear correlation for the analysis of different parameters to describe the structure, such as the beam height to span ratio, short-leg shear wall height to thickness ratio, and steel ratio are introduced. The results show that the height to span ratio directly affects the structural integrity; and the short-leg shear wall height to thickness ratio should be limited to a range of approximately 6.0 to 7.0. The design of short-leg shear walls should be in accordance with the “strong wall and weak beam” principle.

The Influence Study of League Shear Wall Seismic Capacity by the Coupling Wall-Beam Rigidity and Reinforcement Ratio

According to the important role of the league shear wall seismic capacity in the practical engineering, a brief and effective finite element static push-over analysis model was established through using the MIDAS GEN7.95. With the changes in the coupling beam rigidity and reinforcement ratio, the structural base shear, structural failure displacement change during the simulation. On the basis, the curve of the coupling wall-beam rigidity, reinforcement ratio vs. base shear and failure displacement were built respectively. The results show that the coupling wall beam stiffness, reinforcement ratio and league shear wall seismic capacity have a significant effect relationship, which provides an important reference for shear wall seismic design of structures.

Preliminary Analysis on Wall Beam Force Algorithms under the Action of Vertical Load

This paper makes a study on the stress state and internal force algorithms of wall beams under the action of vertical load. It also makes a comparative analysis to several typical wall-beam designs at present. Then, by using the finite element, it verifies the accuracy and reliability of internal force algorithm formulas of wall beams in current Code for Design of Masonry Structure, hoping to provide a solid theoretical reference for the selection of wall beam algorithm designs.

Study on the Floor Damage Model of Hybrid Structure under Seismic Excitation

Structural destroy is a development process that damage is accumulated gradually under earthquake, and the partial destruction leads to the overall damage, even structural collapse finally. Based on the damage model of beam, column and shear wall, the damage is studied from the component level, the most important design parameters which include bending strength ratios of beam to column, xial compression ratio and stiffness characteristic value are researched. Then the finite element numerical analysis software ABAQUS is used to analyze the influence of various component damage on seismic performance of floor. Finally, this paper adopts Weighting Coefficient Method to establish a reasonable model for the floor damage evaluation .It proves that the model can reflect the relationship between component damage and floor damage.

Nonlinear Earthquake Response Analysis of a New RC Frame Multi-Ribbed Composite Walls Structure

A new RC frame multi-ribbed composite walls structure is provided by using low yield strength steel. Two calculating structures are analyzed which one is the RC frame shear wall structure used as a comparison, and the other is the RC frame multi-ribbed composite walls structure. The nonlinear earthquake responses of the structures are calculated by using program IDARC2D.The nonlinear dynamic analysis models of the structures are established with retrogressive three-linear resilience model for beam, column and RC shear wall elements, while a smooth hysteretic model is proposed for representing low yield strength steel panels. The nonlinear dynamic time-history analysis of the structures under horizontal earthquake waves has been carried out. The earthquake responses of the structures and energy dissipation are studied, which provide more data information for the comprehension of earthquake responses and seismic performance of the RC frame multi-ribbed composite walls structure. The calculating results show that the low yield strength steel panels have obvious seismic mitigation effects, and that RC frame multi-ribbed composite walls structure has good seismic capacity.

Application Study on Surface FBG Sensor in Structure Experiment

In the experiment of the behaviour of the connection between steel beam and concrete wall, surface FBG sensor and resistance strain gauge were located at the same measuring point of the flange girth of the steel beam. Measuring results show that the measuring effectiveness of both methods is uniform. And the surface FBG sensor has the merits of using conveniently and non-vitiating. So using surface FBG sensor to measure the surface strains of structural members in structure experiment is feasible.

A Stress Analytical Solution of Steel Reinforced Concrete Transfer Beam

The structural behavior of a steel reinforced concrete (SRC) transfer beam in high-rise building is studied in the paper. Mechanical properties and deformation characteristics between transfer beam and shear wall are analyzed by an analytic approach and the nonlinear finite element method. The stress analytical solutions for the SRC transfer beam are obtained and agree with finite element calculation data in an actual project. The results show that the beam can be as an eccentric tension member, meanwhile the performance of shear wall must be considered. And it also shows that the shear stress and vertical compressed stress must be considered in end both transfer beam and shear wall and there is interaction between the beam and the shear walls above. The results can be used to describe the behavior of the SRC transfer beam under complicated loads.

Nonlinear Static Analysis of RC Shear Wall Structure Based on Opensees

To study the seismic performance of RC shear wall, and to develop its fine nonlinear analysis method, systemic studies on nonlinear static analysis and it’s realization method are carried out. Beginning with rotating-angle softened-truss model for coupled shear and flexural responses, analytical model of solid wall is presented based on the comparative study on four types of constitutive law of concrete for confined concrete of boundary zone. Good agreements between analytical and experimental results of load-displacement relation are found, which indicates that the proposed analytical method can reflect the global mechanical behavior of shear wall well. Studies on coupling beam and global perforated wall modeling are implemented, then modeling approach and nonlinear static analysis method for perforated wall are proposed. Comparing analytical load-displacement curve to experimental, initial stiffness and first turning point agree well and analytical ultimate capacity is close to experimental, which is shown that the load-displacement curve can actually exhibit the general load-displacement trend of perforated wall.