scholarly journals ANALISIS PENGARUH PEMODELAN SAMBUNGAN TITIK BUHUL PADA STRUKTUR KUBAH GEODESIK

2021 ◽  
Vol 4 (2) ◽  
pp. 503
Author(s):  
Rivven Meilvin ◽  
Leo S. Tedianto
Keyword(s):  
Axial Force ◽  
Joint Modeling ◽  
Internal Force ◽  
Cross Sectional ◽  
Axial Forces ◽  
Translational Displacement ◽  
Single Structure ◽  
Dome Structure ◽  
Internal Forces ◽  
Geodesic Dome

The geodesic dome consists of steel rod elements joined together to form a single structure. Generally, these geodesic domes are analyzed by assuming the joints of the gusset points are joints and only receive axial forces on the rods. However, in reality, it is not easy to apply gusset joints as pure joints in construction. This research will analyze the geodesic dome by modeling the joints of the gusset points as joints where there is only axial force arising on the rods and modeling the rigid gusset points where there will also be moments and shear on the rods. The analysis will only be carried out by comparing the value of the displacement at each gusset joint modeling and checking the cross-sectional dimensions of the internal forces that arise with the help of the MIDAS GEN program in modeling the geodesic dome structure which has a diameter of 20000 mm and a height of 10000 mm with the type of steel profile. used is a pipe profile using two types of geodesic dome, namely type 2V and 3V. For loads that are calculated, namely dead load, live load, and wind load. The results showed a relatively small difference in translational displacement and the axial force was relatively the same in the internal force analysis, so it is better if the analysis by modeling the gusset connection as rigid.ABSTRAKKubah geodesik terdiri dari elemen batang baja yang disambung menjadi satu kesatuan struktur. Umumnya kubah geodesik ini dianalisis dengan menganggap sambungan titik buhulnya berupa sendi dan hanya menerima gaya aksial saja pada batang - batangnya. Namun pada kenyataannya untuk mengaplikasikan sambungan titik buhul sebagai sendi murni pada konstruksi tidaklah mudah. Penelitian ini akan menganalisis kubah geodesik   dengan memodelkan sambungan titik buhulnya sebagai sendi dimana hanya ada gaya aksial saja yang timbul pada batang - batangnya dan memodelkan titik buhulnya rigid dimana akan terjadi juga momen dan geser pada batang tersebut. Analisis hanya akan dilakukan dengan membandingkan nilai dari perpindahan pada setiap pemodelan sambungan titik buhul dan pengecekan dimensi penampang terhadap gaya – gaya dalam yang timbul dengan bantuan program MIDAS GEN dalam memodelkan struktur kubah geodesik yang mempunyai diameter 20000 mm dan tinggi 10000 mm dengan jenis profil baja yang digunakan adalah profil pipa dengan menggunakan dua tipe kubah geodesik yaitu tipe 2V dan 3V. Untuk beban yang diperhitungkan yaitu beban mati, beban hidup, dan beban angin. Hasil penelitian menunjukkan nilai perbedaan yang relatif kecil pada perpindahan translasi dan diperoleh gaya aksial yang relatif sama pada analisis gaya dalam yang timbul, sehingga sebaiknya analisis dengan pemodelan sambungan titik buhul sebagai rigid.

Internal Forces and Steel Arrangement Analysis on the Steel Lined Reinforced Concrete Penstocks

2011 ◽  
Vol 94-96 ◽  
pp. 99-104
Author(s):  
Zhang Wei ◽  
Chuan Xiong Fu ◽  
Lu Feng Yang ◽  
Jin Zhang
Keyword(s):  
Reinforced Concrete ◽  
Axial Force ◽  
Cross Sections ◽  
Design Method ◽  
Internal Force ◽  
Concrete Wall ◽  
Inner Radius ◽  
Load Carrying ◽  
Internal Forces ◽  
Axisymmetric Structure

he steel lined reinforced concrete penstocks (SLRCP) is always looked as an axisymmetric structure according to the design code, which can not show the true load-carrying capacity when considering the dam’s constraint to the SLRCP. In this paper, the physical non-axisymmetric property of the structure is simulated using the finite element method. The internal force distribution of every cross section in the SLRCP is studied, and a design method for steel arrangement based on axial force is proposed. When considering the non-axisymmetric property, the axial force in those cross sections approaching the bottom of the structure may be reduced more than 30% to the calculated value by the axisymmetric analysis. The larger the inner radius of the penstock or the thickness of the concrete wall is, the more marked the non-axisymmetric property of the SLRCP is.

scholarly journals Internal and External Forces Measurement of Planar 3-DOF Redundantly Actuated Parallel Mechanism by Axial Force Sensors

ISRN Robotics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Harada ◽  
Podi Liu
Keyword(s):  
Parallel Mechanism ◽  
Force Sensor ◽  
Internal Force ◽  
Time System ◽  
Constraint Force ◽  
Real Time System ◽  
Axial Forces ◽  
Redundantly Actuated ◽  
Internal Forces ◽  
External Forces

This paper proposes a method for measuring the internal and external forces of a planar 3-DOF (degree of freedom) redundantly actuated parallel mechanism. The internal forces, force acts inside the endplate and mechanism constraint force, and the external forces, forces act on the endplate and thrusts by actuators, were measured simultaneously using the axial forces of the rods. Kinetostatic equations of the parallel mechanism were used to derive algorithms for measuring the internal and external forces. A link axis force sensor was developed using a strain gauge sensor. To verify the actual internal force of the endplate, a force sensor was also installed on the endplate. A real-time system for measuring the forces of the parallel mechanism was developed using RT-Linux. The external and internal forces were measured accurately.

Calculation on Internal Force Effect of a High-Speed Highway Prestressed Concrete Extra-Dosed Cable-Stayed Bridge

2014 ◽  
Vol 580-583 ◽  
pp. 3154-3157
Author(s):  
Xing Zhou Chen
Keyword(s):  
Prestressed Concrete ◽  
High Speed ◽  
Element Model ◽  
Internal Force ◽  
Bridge Structure ◽  
Cross Sectional ◽  
Cable Stayed Bridge ◽  
Rigid Frame ◽  
Internal Forces ◽  
Design Speed

The Extra-dosed cable-stayed bridge is considered as a new popular type of bridge structure in recent 20 years, whose mechanical properties and economic span both lie between continuous beam (or rigid frame ) bridges and cable-stayed bridges. This design is a double-cable-plane (85+150+85) m prestressed concrete Extra-dosed cable-stayed bridge, whose maximum Design speed is 100km/h and its width is 25.50m. The form of the highway is sextuple line which is 10.75m far away,and the cross-sectional slope is 2%. The girder body adopts three cell and single box, the height of beam takes quadratic parabola relation, which is 5m high at the middle support, while at the side support and the midspan is 3m. Vehicle standard load was applied on the bridge. The design uses Midas/Civil to establish the finite element model that is reasonable and simple, analyzing the structure behavior of the girder body under loading, especially the internal forces of bridge structure under dead load, live load and additional force.

Calculation on Plastic Internal Force of Reinforced Concrete Member under Axial Force

2014 ◽  
Vol 578-579 ◽  
pp. 31-36
Author(s):  
Er Jun Wu ◽  
Xing Chen
Keyword(s):  
Reinforced Concrete ◽  
Axial Force ◽  
Concrete Structure ◽  
Maximum Error ◽  
Internal Force ◽  
Reinforced Concrete Structure ◽  
Concrete Member ◽  
Elastic Plastic ◽  
Reinforced Concrete Member ◽  
Internal Forces

The design of reinforced concrete structure often used the elastic internal force as the design basis, but the nonlinear behavior of reinforced concrete structures brings about errors in calculation of statically indeterminate structure. By considering the nonlinear properties, the mechanical responses of reinforced concrete structure were investigated, on which an axial force loaded at their middle span section. In a series of analysis on internal force of the reinforced concrete member at all loading stages, through the deformation compatibility equation and the balance equation, the formulas for calculating elastic-plastic internal forces and strains were derived. Comparative examples are provided and the results show a large error between internal forces calculated by the structural mechanics method and those by the elastic-plastic method proposed in this paper, and the maximum error is about 8 times.

Investigation on the free vibration behavior of sandwich conical shells with reinforced cores

2021 ◽  
pp. 109963622110204
Author(s):  
Mehdi Zarei ◽  
Gholamhossien Rahimi ◽  
Davoud Shahgholian-Ghahfarokhi
Keyword(s):  
Free Vibration ◽  
Orientation Angle ◽  
Element Model ◽  
Filament Winding ◽  
Vertex Angle ◽  
Sandwich Shell ◽  
Cross Sectional ◽  
Conical Shells ◽  
Vibration Behavior ◽  
Axial Forces

The free vibration behavior of sandwich conical shells with reinforced cores is investigated in the present study using experimental, analytical, and numerical methods. A new effective smeared method is employed to superimpose the stiffness contribution of skins with those of the stiffener in order to achieve equivalent stiffness of the whole structure. The stiffeners are also considered as a beam to support shear forces and bending moments in addition to the axial forces. Using Donnell’s shell theory and Galerkin method, the natural frequencies of the sandwich shell are subsequently derived. To validate analytical results, experimental modal analysis (EMA) is further conducted on the conical sandwich shell. For this purpose, a method is designed for manufacturing specimens through the filament winding process. For more validation, a finite element model (FEM) is built. The results revealed that all the validations were in good agreement with each other. Based on these analyses, the influence of the cross-sectional area of the stiffeners, the semi-vertex angle of the cone, stiffener orientation angle, and the number of stiffeners are investigated as well. The results achieved are novel and can be thus employed as a benchmark for further studies.

Structural Analysis and Internal Force Calculation of Variable Cross-Section Silo

2012 ◽  
Vol 446-449 ◽  
pp. 429-434
Author(s):  
Rui Ting Ma
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
Internal Force ◽  
Variable Cross ◽  
Axially Symmetric ◽  
Internal Forces ◽  
Differential Element ◽  
Symmetric Load ◽  
Force Calculation ◽  
Constant Section

In this paper, the differential element of constant-section silo wall suffering from axially symmetric load is analyzed. From the results of constant-section silo, the author derives the displacements and internal forces of variable cross-section silo. Through a specific example, this paper compares the displacements , internal forces and concrete consumption of variable cross-section silo with those of constant-section silo, and discusses the merits of variable cross-section silo.

The optimization process leading to the tessellation of the first geodesic dome structure, the first Planetarium of Jena

2021 ◽  
pp. 095605992110641
Author(s):  
Orsolya Gáspár
Keyword(s):  
Exact Solution ◽  
Simple Algorithm ◽  
Edge Length ◽  
Optimization Process ◽  
Length Ratio ◽  
Theoretical Studies ◽  
Equal Area ◽  
Geodesic Domes ◽  
Dome Structure ◽  
Geodesic Dome

The tessellation of the first built geodesic dome structure (the first planetarium of Jena, designed by Walther Bauersfeld, built 1922–23) has been unknown until recently. While original documentation of the tessellation has been published, the concept behind it has not been uncovered. This article presents the evolution of the final tessellation based on Bauersfeld’s hand-written notes found in the Zeiss Archives in Jena. Bauersfeld contemplated various methods of subdivision and performed detailed calculations and optimality analysis on them—preceding the theoretical studies on the tessellation of geodesic domes by almost 30 years. His key findings, relevant and comparable with later studies are highlighted. The concept of the presumably final tessellation is revealed to be the equal-area triangulation of the sphere—which has to the author’s knowledge not been considered ever since for geodesic domes. The remarkably simple algorithm applied did not result in a theoretically exact solution (well known to Bauersfeld), but as shown in this article in engineering terms it got sufficiently close. Moreover, it is concluded that the resulting tessellation excels in terms of important parameters (e.g. edge length ratio, number of different edges) compared to existing practical and theoretical solutions.

Advances In The Modeling And Dynamic Simulation of Reeving Systems Using The Arbitrary Lagrangian-Eulerian Modal Method

2021 ◽  
Author(s):  
José L. Escalona ◽  
Narges Mohammadi
Keyword(s):  
Finite Elements ◽  
Axial Force ◽  
Axial Direction ◽  
Rotary Inertia ◽  
Arbitrary Lagrangian Eulerian ◽  
Original Formulation ◽  
Absolute Position ◽  
Axial Forces ◽  
Modal Coordinates ◽  
Modal Method

Abstract This paper presents new advances in the arbitrary Lagrangian-Eulerian modal method (ALEM) recently developed for the systematic simulation of the dynamics of general reeving systems. These advances are related to a more convenient model of the sheaves dynamics and the use of axial deformation modes to account for non-constant axial forces within the finite elements. Regarding the sheaves dynamics, the original formulation uses kinematic constraints to account for the torque transmission at the sheaves by neglecting the rotary inertia. One of the advances described in this paper is the use of the rotation angles of the sheaves as generalized coordinates together with the rope-to-sheave no-slip assumption as linear constraint equations. This modeling option guarantees the exact torque balance the sheave without including any non-linear kinematic constraint. Numerical results show the influence in the system dynamics of the sheave rotary inertia. Regarding the axial forces within the finite elements, the original formulation uses a combination of absolute position coordinates and transverse local modal coordinates to account for the rope absolute position and deformation shape. The axial force, which only depends on the absolute position coordinates, is constant along the element because linear shape functions are assumed to describe the axial displacements. For reeving systems with very long rope spans, as the elevators of high buildings, the constant axial force is inaccurate because the weight of the ropes becomes important and the axial force varies approximately linearly within the rope free span. To account for space-varying axial forces, this paper also introduces modal coordinates in the axial direction. Numerical results show that a set of three modal coordinates in the axial direction is enough to simulate linearly varying axial forces.

scholarly journals The Use of the Collocation Algorithm for Estimating the Deformations of Soil-Shell Objects Made of Corrugated Sheets

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Czesław Machelski
Keyword(s):  
Strain Gauges ◽  
Boundary Constraints ◽  
Axial Forces ◽  
Collocation Points ◽  
Geodetic Measurements ◽  
Significant Divergence ◽  
Internal Forces ◽  
Support Conditions ◽  
Static Conditions ◽  
The Impact

AbstractThe algorithm presented in this paper is intended for the analysis of deformations of shells in the construction phase of soil-shell objects when strain gauges and geodetic measurements are used. During the construction of such an object, large displacement values occur and the impact of axial forces on the displacement of a corrugated metal sheet is small. Internal forces (strain gauges), as well as the displacements of a selected circumferential band of the shell are determined directly from such observations.The paper presents two examples of the analysis of large span shell structures of constructed objects, as well as the assessment of the effectiveness of the finite difference method (FDM) in beam schemes. Good deformation mapping was indicated using the collocation algorithm and the differential approach to the solution when there is a dense mesh and regular distribution of measuring points. In the analysed examples, a significant divergence between the support conditions adopted in the FEM calculation models and the actual static conditions in the objects was indicated. The collocation algorithm is especially designed for such situations. Collocation points in such a solution are used to consider a beam – separated from a structure and without boundary constraints, but with specific changes in curvature – as a reference system, which is determined from the geodetic measurements of two collocation points.

An Analytical Solution for Transversely Isotropic Simply Supported Thick Rectangular Plates Using Displacement Potential Functions

2011 ◽  
Vol 46 (2) ◽  
pp. 121-142 ◽  
Author(s):  
M Nematzadeh ◽  
M Eskandari-Ghadi ◽  
B Navayi Neya
Keyword(s):  
Isotropic Material ◽  
Transversely Isotropic ◽  
Numerical Results ◽  
Potential Functions ◽  
Constant Thickness ◽  
Rectangular Plates ◽  
Displacement Potential ◽  
Simply Supported ◽  
Axial Forces ◽  
Internal Forces

Using a complete set of displacement potential functions, the exact solution of three-dimensional elasticity equations of a simply supported rectangular plates with constant thickness consisting of a transversely isotropic linearly elastic material subjected to an arbitrary static load is presented. The governing partial differential equations for the potential functions are solved through the use of the Fourier method, which results in exponential and trigonometric expression along the plate thickness and the other two lengths respectively. The displacements, stresses, and internal forces are determined through the potential functions at any point of the body. To prove the validity of this approach, the analytical solutions developed in this paper are degenerated for the simpler case of plates containing isotropic material and compared with the existing solution. In addition, the numerical results obtained from this study are compared with those reported in other researches for the isotropic material, where excellent agreement is achieved for both thin and thick plates. The results show that increasing the thickness ratios of the plate causes compressive axial forces and central shear forces inside the plate. Finally, the internal forces and displacement components are calculated numerically for several kinds of transversely isotropic materials with different anisotropies and are compared with a finite element (FE) solution obtained from the ANSYS software, where the high accuracy of the present method is demonstrated. The effects of the material anisotropy are clearly revealed in the numerical results presented.

Sign in / Sign up

Export Citation Format

Share Document