scholarly journals Masonry Dome Behavior under Gravity Loads Based on the Support Condition by Considering Variable Curves and Thicknesses

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 241
Author(s):  
Asem Sharbaf ◽  
Mohammadreza Bemanian ◽  
Khosro Daneshjoo ◽  
Hamzeh Shakib
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Hoop Stress ◽  
Shell Theory ◽  
Boundary Line ◽  
Support Condition ◽  
Significant Parameter ◽  
The Past ◽  
Masonry Domes ◽  
Masonry Dome

It is necessary to recognize masonry domes’ behavior under gravity loads in order to strengthen, restore, and conserve them. The neutral hoop plays a crucial role in identifying the masonry dome’s behavior to distinguish between its tensile and compressive regions. When it comes to determining the neutral hoop position in a dome with the same brick material, in addition to determining the dome’s curve and thickness, the support condition located on the boundary line is a significant parameter that has received less attention in the past. Therefore, this research aims to comprehensively define masonry dome behaviors based on the support condition’s effect on the masonry dome’s behavior, in addition to thickness and curve parameters, by determining neutral hoop(s). The method is a graphical and numerical analysis to define the sign-changing positioning in the first principal stress (hoop stress), based on the shell theory and extracted from a finite element method (FEM) Karamba3D analysis of a macro-model. The case studies are in four types of supports: condition fixed, free in the X- and Y-axes, free in all axes (domes placed on a drum), and free in all axes (domes placed on a pendentive and a drum). For each support condition, twelve curves and four varied thicknesses for each curve are considered. Results based on the dome’s variables show that, in general, four types of masonry domes behavior can be identified: single-masonry dome behavior with no neutral hoop; double-masonry dome behavior where all hoops are compressive with a single neutral hoop; double-masonry dome behavior where hoops are compressive and tensile with a single neutral hoop; and treble-masonry dome behavior with double neutral hoops.

Curling Stress Equation for Transverse Joint Edge of a Concrete Pavement Slab Based on Finite-Element Method Analysis

1996 ◽  
Vol 1525 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Tatsuo Nishizawa ◽  
Tadashi Fukuda ◽  
Saburo Matsuno ◽  
Kenji Himeno
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fem Analysis ◽  
Concrete Pavement ◽  
Winkler Foundation ◽  
Stress Equation ◽  
The Past ◽  
Transverse Joint ◽  
Foundation Model ◽  
Element Method

In the design of concrete pavement, curling stresses caused by the temperature difference between the top and bottom surfaces of the slab should be calculated at the transverse joint edge in some cases. However, no such equation has been developed in the past. Accordingly, a curling stress equation was developed based on stress analysis using the finite-element method (FEM). In this FEM analysis, a concrete pavement and its transverse joint were expressed by means of a thin plate–Winkler foundation model and a spring joint model, respectively. Multiregression analysis was applied to the results of the FEM numerical calculation and, consequently, a curling stress equation was obtained. After comparing the calculated results of the equation with curling stress equations developed in the past, it was confirmed that the equation was valid and practical.

Application of CAD and Finite Element Method in the Gravity Center Analysis of Body Rotating Cable-Stayed Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1549-1552
Author(s):  
Shi Jie Wang ◽  
Xun Zhu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rotation Axis ◽  
Center Of Gravity ◽  
Accurate Calculation ◽  
Gravity Center ◽  
The Past ◽  
Cable Stayed Bridge ◽  
Rotation System ◽  
Element Method

Body rotating bridges are mostly rotation system in balance, whose gravity center are basically located in the rotation axis of turntable. In order to ensure bridges’ swivel construction successfully accomplished, the structural center of gravity should be made clear before the rotation. In the past, the structural center of gravity was usually ascertained in the method of mathematics, but the tedious calculation couldn’t get results with enough accuracy. In this paper, structural gravity center of cable-stayed bridge is calculated in the method of CAD and finite element, whose process and result are proved handy and accurate calculation. Taking Sui Fenhe cable-stayed bridge as an example, its theoretical eccentricity is 1.3cm.

A Study of Hydroformed Bellows, Applying a Finite Element Method: Relationship of Bellows Dimensions, Shape, Spring Rate and Stress

1991 ◽  
Author(s):  
Asahiko Ishiyama ◽  
Yoshihiro Suefuji ◽  
Masato Yonemitsu ◽  
Akira Ura
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shell Theory ◽  
Maximum Shear Stress ◽  
Calculation Model ◽  
Uniform Thickness ◽  
Spring Rate ◽  
Energy Theory ◽  
Relationship Of ◽  
Element Method

Abstract The spring rate of hydroformed bellows are generally calculated by shell theory or energy theory. In both cases, the calculation model of the bellows will be simplified and the thickness of the bellows convolutions will be assumed as a uniform thickness plate. It is often found that calculated solutions differ from experimental spring rates and stresses since the outside thickness of the bellows is different to the inside thickness. In this paper a finite element method (FEM) is applied to obtain the spring rate and stress of bellows. The calculated spring rates are almost the same as those of experimental data and indicate that the spring rate value is very sensitive to the ratio of OD thickness and ID thickness. The design diagrams for spring rate and maximum shear stress reflecting OD and ID thickness ratio are therefore presented.

Parametric Finite Element Method for Predicting Shapes of Three-Dimensional Solder Joints

1996 ◽  
Vol 118 (3) ◽  
pp. 142-147 ◽  
Author(s):  
N. J. Nigro ◽  
F. J. Zhou ◽  
S. M. Heinrich ◽  
A. F. Elkouh ◽  
R. A. Fournelle ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Solder Joints ◽  
Three Dimensional ◽  
Potential Energy Function ◽  
Vertical Force ◽  
The Past ◽  
Nodal Coordinates ◽  
Blending Functions ◽  
Element Method

This paper discusses the application of the parametric finite element method for predicting shapes of three-dimensional solder joints. With this method, the surface of the joint is meshed (discretized) with finite elements. The spatial variables (x, y, z) are expanded over each element in terms of products of interpolation (blending) functions expressed in parametric form and element nodal coordinates. The element nodal coordinates which are not constrained by the boundary conditions are determined by minimizing the potential energy function which governs the joint formation problem. This method has been employed successfully in the past to predict the shapes of two dimensional fillet and axisymmetric joints. In this paper, the method is extended to three dimensional problems involving sessile drops formed on a rectangular pad and solder columns formed between two horizontal planes and subject to a vertical force.

Assessment of Error and Pressure Influence on Total Equivalent Stress Amplitude Calculation by WRC107

2011 ◽  
Author(s):  
Fujun Liu ◽  
Yueqiang Qian ◽  
Zhangwei Ling ◽  
Shuai Kong ◽  
Mulin Zheng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shell Theory ◽  
Stress Amplitude ◽  
Equivalent Stress ◽  
External Loading ◽  
Calculation Error ◽  
Fatigue Evaluation ◽  
Chinese Standard ◽  
Equivalent Stress Amplitude

Bulletin WRC107 is most commonly used in attachment design, but still some uncertainties make it difficult to ensure safety in recent use. Two problems in fatigue evaluation were addressed here, first the bulletin is based on shell theory and some other assumption, and for various condition the calculation error is unknown; second pressure is not considered in calculation. To the first problem, an assessment was performed by comparing the total equivalent stress results of WRC107 and of finite element method (FEM). To the second problem, a method from Chinese standard HG20582-1998 Specification for Stress Calculation of Steel Chemical Vessels (HG method) was introduced as a supplement, and the reliability was studied. The results show that, total equivalent stress amplitude calculated by WRC107 may be underestimated, and its error mainly depends on parameters β and γ. Complemented by HG method, WRC107 could be used in calculation of shell under pressure and external loading.

Hoop Stress Analysis of High Grade Heavy Wall Thickness Pipe in Hydrostatic Test

2011 ◽  
Vol 287-290 ◽  
pp. 2826-2829
Author(s):  
Yan Hua Yang ◽  
Zhuan Zhao Yang ◽  
Xing Liang Liu ◽  
Hao Xue Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Hydrostatic Pressure ◽  
Theoretical Calculation ◽  
Wall Thickness ◽  
Hoop Stress ◽  
Stress Gradient ◽  
Line Pipe ◽  
Inner Diameter ◽  
Element Method

The distribution of hoop stress calculated and simulated by Finite Element Method and theoretical calculation in this paper, when the hydrostatic pressure was carried out on the line pipe of Φ 762mm×31.8 mm API SPEC 5L[1] X70 longitudinal seams submerged arc welding(LSAW). The results of simulated by Finite Element Method were accord well with that of theoretical calculation, both of them shown that the hoop stress deviation between pipe inside surface and outside surface was nearly 40MPa, which was about 9% of the hoop stress of outside surface. Besides, the influence of the D/t(diameter-thickness ratio)on the hoop stress were also researched, which shown that the larger the value of D/t was , the fewer that influence on the hoop stress, when D/t=200, the deviation was less than 1%; Or else, the D/t may cause a great stress gradient in the direction of the thickness, even when the D/t=42, the deviation was up to 5%. So that, the effect of the d/t should be taken into account when calculating the hoop stress of pipe with D/t≤42. In other word, a new hydrostatic pressure formula for the heavy wall thickness pipe( D/t≤42) was put forward and adopted when calculating its hydrostatic pressure, that was P =c* Sh (Do2 - Di2) / (Do2 + Di2), where, c, specification coefficient; Sh, hoop stress; Do, outside diameter; Di, inner diameter.

Finite Element Thrust Line Analysis (FETLA) of Axisymmetric Masonry Dome with Meridian Cracks

2017 ◽  
Vol 865 ◽  
pp. 397-402 ◽  
Author(s):  
Mahesh Varma ◽  
Siddhartha Ghosh ◽  
Gabriele Milani
Keyword(s):  
Finite Element ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Tensile Forces ◽  
Ring Mechanism ◽  
Masonry Domes ◽  
Tension Cracks ◽  
The Stability ◽  
Masonry Dome ◽  
Line Analysis

Many masonry domes in their lower portion are subjected to hoop tensile forces which mostly lead to vertical cracks appearing along the dome's meridian planes. A close inspection of any such dome reveals these hoop tension cracks. The dome stands as a series of arches with common key stone, with cracks as a matter of non-structural consequences. Different strategies have been considered historically to arrest these cracks. The provision of tension ring mechanism adds to the stability of these domes, and hence many masonry domes are retrofitted with the provision of the tension rings using steel and FRP rings. The challenge in such retrofitting will remain to analyze its effect on stability of these masonry domes, more specifically in absence of reliable mechanical properties of such masonry domes. This paper presents a simplified analysis procedure combining thrust line analysis with the finite element analysis called here as Finite Element Thrust Line Analysis (FETLA). The development of a new element suitable for masonry dome analysis to include the effect of hoop tension cracks is demonstrated. The orthotropic material properties are utilized for penalty approach to allow redistribution of the forces from meridian direction to the hooping rings, with thrust line approaching the extrados or intrados of the dome. The analysis results of FETLA are validated with the previously available results. The analysis method proposed in this paper gives the rational estimates for the failure load without utilizing inelastic properties of the material to model the hoop tension cracks and its propagation.

scholarly journals Sinkhole Hazard Caused by Inactive Mining Shafts as Illustrated by a Selected Example

2021 ◽  
Author(s):  
Piotr Strzałkowski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rock Material ◽  
Loss Of Stability ◽  
Intense Rainfall ◽  
The Past ◽  
Ex Post ◽  
Future Direction ◽  
Sinkhole Hazard

AbstractLoss of stability of shafts liquidated in the past is a frequent cause of sinkhole creation on the surface. This manuscript presents such a case study. The sinkhole was created shortly after intense rainfall, so it can be assumed that displacement of the rock material in the shaft took place, i.e. the phenomenon of suffusion. One of the research aims was to confirm the assumption about the displacement of rock material filling the shaft on the basis of selected methods of sinking forecasting. Ex post forecast sinkhole creation was conducted using two methods (Bell and finite element method). It was assumed that the material filling the shaft lowered itself to a height determined on the basis of the sinkhole and shaft dimensions. Both methods gave the same results, consistent with the literature . The manuscript also presents a short overview of technologies used for decommissioning shafts and assesses their effectiveness in terms of preventing sinkhole creation. These methods have been used since the nineteenth century until present times. Considering the suffusion phenomenon, the paper proposes a way to drain rainwater from the shaft area, which was another purpose of the work. The necessity to find and verify the ways to secure decommissioned shafts from water is indicated as an important future direction of research.

scholarly journals Analysis Beam-Column Cellular By Finite Element Method

10.29007/s1rd ◽  
2022 ◽  
Author(s):  
Minh Duc Nguyen ◽  
Thai Hien Nguyen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Web Openings ◽  
Telephone Networks ◽  
The Past ◽  
Post Buckling ◽  
The Subject ◽  
Element Method

Nowadays in the construction of modem buildings, it is necessary to accommodate pipes and ducts necessary services, such as air conditioning, water supply, sewerage, electricity, computer networks, and telephone networks. Cellular members – steel I‐ shaped structural elements with circular web openings at regular intervals – have been used as beams for more than 35 years now. Although in the past already a large deal of research was performed into the subject of the behavior of cellular beams, almost no attention has been paid to the application of cellular members as columns. The column will be analyzed using the finite element method to calculate the critical load and compared with the Eurocode3 standard, web-post buckling, and frame using cellular member by FEM.

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