scholarly journals Investigation of Shear Stiffness of Spine Bracing Systems in Selective Pallet Racks

2015 ◽  
Vol 9 (1) ◽  
pp. 1-6
Author(s):  
Bo Cheng ◽  
Zhenyu Wu
Keyword(s):  
Steel Structure ◽  
Shear Stiffness ◽  
Local Deformation ◽  
Deformation Analysis ◽  
Simplified Models ◽  
Beam Elements ◽  
Single Entry ◽  
Lateral Behavior ◽  
Double Entry ◽  
Selective Storage

This paper presents a general analysis on the shear stiffness of spine bracing systems of selective storage racks in the down-aisle direction. Unlike the architectural steel structure, the bearing capacity of bracing connection in the spine bracing systems of steel rack structure is weaker than that of bracing members. Firstly, destructive tests of spine bracing connection in single entry racks have been conducted. In the tests, a portion of column web around bolt holes is damaged due to the pull force of connecting bolts. Based on the experimental results, the finite element shell model of tested bracing connection is developed, and the emulation method is also used to analyze the deformation behavior of spine bracing connections in double entry racks. The calculating results indicate that, with better mechanical behavior and less local deformation, the tensile stiffness of bracing connection in double entry racks is much larger than that of bracing connection in single entry racks. From the trial calculation, the simplified models using elastic plastic beam elements are proposed. These simplified models can be adopted in the overall deformation analysis of selective pallet racks subjected to horizontal loading. Through the comparative analysis of single entry racks and double entry racks which have four bays and eight floors, the lateral deformation of double entry racks is considerably less than that of single entry racks, showing the large different effect of spine bracing systems on two rack lateral behavior.

scholarly journals A New Approach for Cylindrical Steel Structure Deformation Monitoring by Dense Point Clouds

2021 ◽  
Vol 13 (12) ◽  
pp. 2263
Author(s):  
Dongfeng Jia ◽  
Weiping Zhang ◽  
Yuhao Wang ◽  
Yanping Liu
Keyword(s):  
Steel Structure ◽  
Steel Structures ◽  
Point Clouds ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Relative Deformation ◽  
Structure Deformation ◽  
Single Time ◽  
Cylindrical Steel ◽  
Cylinder Fitting

As fundamental load-bearing parts, the cylindrical steel structures of transmission towers relate to the stability of the main structures in terms of topological relation and performance. Therefore, the periodic monitoring of a cylindrical steel structure is necessary to maintain the safety and stability of existing structures in energy transmission. Most studies on deformation analysis are still focused on the process of identifying discrepancies in the state of a structure by observing it at different times, yet relative deformation analysis based on the data acquired in single time has not been investigated effectively. In this study, the piecewise cylinder fitting method is presented to fit the point clouds collected at a single time to compute the relative inclination of a cylindrical steel structure. The standard deviation is adopted as a measure to evaluate the degree of structure deformation. Meanwhile, the inclination rate of each section is compared with the conventional method on the basis of the piecewise cylinder fitting parameters. The validity and accuracy of the algorithm are verified by real transmission tower point cloud data. Experimental results show that the piecewise cylinder fitting algorithm proposed in this research can meet the accuracy requirements of cylindrical steel structure deformation analysis and has high application value in the field of structure deformation monitoring.

Micro Parameters Sensitivity of Coarse Grained Material in Mechanics and Deformation Based on PFC3D

2016 ◽  
Vol 873 ◽  
pp. 115-119
Author(s):  
Zhi Hua Zhang ◽  
Xie Dong Zhang ◽  
Hong Sheng Qiu ◽  
Bei Yang Zhang
Keyword(s):  
Weighted Average ◽  
Shear Stiffness ◽  
Coarse Grained ◽  
Triaxial Tests ◽  
Deformation Analysis ◽  
Analysis Method ◽  
Particle Rotation ◽  
Sensitivity Curves ◽  
Coarse Grained Material ◽  
Strength And Deformation

In order to study the effects of various parameters on macro-mechanical and deformational characteristics of coarse grained material based on discrete element method, triaxial tests have been conducted. Weighted average assembling method is used to assemble the numerical model based on PFC3D. The ratio of normal and shear stiffness of particles (kn/ks), shearing rate and friction coefficient are chosen as micro parameters to analyze the influential sensitivity. Curves of stress-strain intensity are taken as the mechanical analytic method. The particle rotation field as deformation analysis method is proposed to sort the sensitivity of these parameters in strength and deformation of coarse grained material. The research shows that the parameters have a certain effect on the strength and deformation of coarse grained material. kn/ks has the greatest influence on both. The sensitive list of the strength and deformation hopefully can be discussed with the relevant scholars, which can provide a reference for the adjustment of micro parameters in numerical field.

Development and Validation of Offset Deformable Barrier Model with Beam Element

2011 ◽  
Vol 128-129 ◽  
pp. 1139-1142
Author(s):  
Li Bo Cao ◽  
Wen Tao Cheng ◽  
Xiang Nan Shi ◽  
Jie Chen ◽  
Li Quan
Keyword(s):  
Element Model ◽  
Local Deformation ◽  
Deformation Characteristics ◽  
Static Compression ◽  
Shell Elements ◽  
Sled Test ◽  
Beam Elements ◽  
Development And Validation ◽  
The Finite Element Model ◽  
Quasi Static Compression

According to GB/T 20913-2007 regulation, the finite element model of the offset deformable barrier (ODB) was built with beam and shell elements, and validated in the simulation of quasi-static compression test. In order to analyze the local deformation characteristics of the ODB model, a sled test was designed. A cylinder impactor of 110 mm in diameter was welded in front of the sled. It was used to impact the fixed ODB. The simulation model of this test was also built. The acceleration of the sled and the deformation of the ODB were measured in the test and compared with the simulation data. The results show that the ODB model with beam elements not only satisfies the demands of the regulations, but also has good local deformation characteristics. The efficiency of computing can be improved obviously with beam elements.

scholarly journals Double entry bookkeeping vs single entry bookkeeping

2016 ◽  
Vol 73 (2) ◽  
pp. 282
Author(s):  
Ileana Andreica
Keyword(s):  
Financial Management ◽  
Comparison Method ◽  
Accounting System ◽  
Accounting Systems ◽  
Legal Personality ◽  
Advantages And Disadvantages ◽  
Family Enterprises ◽  
Hypothetical Data ◽  
Single Entry ◽  
Double Entry

Abstract: A financial management eficiently begin, primarily, with an accounting record kept in the best possible conditions, this being conditioned on the adoption of a uniform forms, rational, clear and simple accounting. Throughout history, there have been known two forms of accounting: the simple and double entry. Romanian society after 1990 underwent a substantial change in social structure, the sector on which put a great emphasis being private, that of small manufacturers, peddler, freelance, who work independently and authorized or as associative form (family enterprises, various associations (owners, tenants, etc.), liberal professions, etc.). They are obliged to keep a simple bookkeeping, because they have no juridical personality. Companies with legal personality are required to keep double entry bookkeeping; therefore, knowledge and border demarcation between the two forms of organisation of accounting is an essential. The material used for this work is mainly represented by the financial and accounting documents, by the analysis of the economic, by legislative updated sources, and as the method was used the comparison method, using hypothetical data, in case of an authorized individual and a legal entity. Based on the chosen material, an authorized individual (who perform single entry accounting system) and a juridical entity (who perform double entry accounting system) were selected comparative case studies, using hypothetical data, were analysed advantages and disadvantages in term of fiscal, if using two accounting systems, then were highlighted some conclusion that result.

Comparison of Single-Entry and Double-Entry Two-Step Couple Screening for Cystic Fibrosis Carriers

1996 ◽  
Vol 46 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Leo P. ten Kate ◽  
Joke B.G.M. Verheij ◽  
Mark F. Wildhagen ◽  
Henk B.M. Hilderink ◽  
Loes Kooij ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Single Entry ◽  
Double Entry

A Method of Map Extrapolation for Unequal and Partial Admission in a Double Entry Turbine

2013 ◽  
Author(s):  
Peter Newton ◽  
Alessandro Romagnoli ◽  
Ricardo Martinez-Botas ◽  
Colin Copeland ◽  
Martin Seiler
Keyword(s):  
Velocity Ratio ◽  
Test Stand ◽  
Turbine Wheel ◽  
Turbine Performance ◽  
Admission Data ◽  
Partial Admission ◽  
Single Entry ◽  
Data Points ◽  
Double Entry ◽  
The Impact

This paper presents a method for prediction of the unequal admission performance of a double entry turbine based on the full admission turbine maps and a minimal number of unequal admission points. The double entry turbine has two separate inlet ports which feed a single turbine wheel: this arrangement can be beneficial in a turbocharger application; however the additional entry does add complexity in producing a complete turbine map which includes unequal admission behaviour. When a double entry turbine is operated under full admission conditions, with both entries feeding the turbine equally, this will act effectively as a single entry device and the turbine performance can be represented by a standard turbine map. In reality a multiple entry turbine will spend the majority of time operating under varying degrees of unequal admission, with each entry feeding the turbine different amounts; the extent of this inequality can have a considerable impact on turbine performance. In order to produce a full map which extends from full admission through to the partial admission case (where one inlet has no flow) a large number of unequal admission data points are required. The paper starts by discussing previous attempts to describe the partial and unequal admission performance of a double entry turbine. The full unequal admission performance is then presented for a nozzled, double entry turbine. The impact of unequal admission on turbine performance is demonstrated. Under some conditions of operation, the turbine efficiency may be less than half that of the equivalent full admission case based on the average turbine velocity ratio. A method of using the steady, equal admission maps, with a limited number of unequal admission data points, to predict the full unequal admission behaviour is presented. A good agreement is found when the map extension method is validated against the full unequal admission turbine performance measured on a test stand. In the prediction of efficiency a mean error of approximately 0.39% is found between the test stand data and the proposed extrapolation method, with a standard deviation of 2.79%. A better agreement is generally found at conditions of higher power.

Accounting in state-owned companies operated for the production and sale of alcohol in Russia in the fifteenth-seventeenth centuries

2019 ◽  
Vol 24 (3) ◽  
pp. 425-443 ◽  
Author(s):  
Viatcheslav Sokolov ◽  
Svetlana Karelskaia ◽  
Ekaterina Zuga
Keyword(s):  
Seventeenth Century ◽  
Accounting System ◽  
Alcohol Production ◽  
Single Entry ◽  
History Of ◽  
Double Entry

The purpose of this study is to research the accounting method used in state-owned companies operated for alcohol production and sale in Russia in the fifteenth–seventeenth centuries. Such an accounting method was distinguished by a variety of registers and entries according to a single-entry bookkeeping system. By the seventeenth century, this method had provided a framework for the emergence of a complex accounting system based on the principles of cameral accounting. This study presents the history of an accounting method used in state-owned companies in Russia before the advent of double-entry bookkeeping.

Three Dimensional Absolute Nodal Coordinate Formulation for Beam Elements: Theory

2000 ◽  
Vol 123 (4) ◽  
pp. 606-613 ◽  
Author(s):  
Ahmed A. Shabana ◽  
Refaat Y. Yakoub
Keyword(s):  
Coordinate System ◽  
Absolute Nodal Coordinate Formulation ◽  
Mass Matrix ◽  
Local Coordinate System ◽  
Three Dimensional ◽  
Deformation Analysis ◽  
Large Element ◽  
Absolute Nodal Coordinate ◽  
Beam Elements ◽  
Highly Nonlinear

The description of a beam element by only the displacement of its centerline leads to some difficulties in the representation of the torsion and shear effects. For instance such a representation does not capture the rotation of the beam as a rigid body about its own axis. This problem was circumvented in the literature by using a local coordinate system in the incremental finite element method or by using the multibody floating frame of reference formulation. The use of such a local element coordinate system leads to a highly nonlinear expression for the inertia forces as the result of the large element rotation. In this investigation, an absolute nodal coordinate formulation is presented for the large rotation and deformation analysis of three dimensional beam elements. This formulation leads to a constant mass matrix, and as a result, the vectors of the centrifugal and Coriolis forces are identically equal to zero. The formulation presented in this paper takes into account the effect of rotary inertia, torsion and shear, and ensures continuity of the slopes as well as the rotation of the beam cross section at the nodal points. Using the proposed formulation curved beams can be systematically modeled.

scholarly journals Local Deformation Analysis in Martensite Layer of High-Strength Multilayered Steel Composite Using Synchrotron X-ray Diffraction

2017 ◽  
Vol 66 (6) ◽  
pp. 420-426
Author(s):  
Mayumi OJIMA ◽  
Ayumi SHIRO ◽  
Hiroshi SUZUKI ◽  
Junya INOUE ◽  
Takahisa SHOBU ◽  
...  
Keyword(s):  
High Strength ◽  
Local Deformation ◽  
Deformation Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Martensite Layer ◽  
Steel Composite
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