Numerical Modelling of Historic Vaulted Timber Structures

2013 ◽  
Vol 778 ◽  
pp. 517-525 ◽  
Author(s):  
Carina Fonseca Ferreira ◽  
Dina D’Ayala ◽  
Jose L. Fernandez Cabo ◽  
Rafael Díez
Keyword(s):  
Finite Element Method ◽  
Software Package ◽  
Structural Response ◽  
Shear Stiffness ◽  
Timber Structure ◽  
Structural Performance ◽  
Timber Structures ◽  
Global Response ◽  
Historic Structures ◽  
Numerical Approaches

Historic timber structures forming vaulted roofs of public and ecclesiastical buildings are present worldwide. The structural response of these constructions is usually governed by the structural performance of the joints, the interaction between the timber structure and the masonry parts, and the current condition of both joints and timber members. At present, numerical approaches, such as finite element method-based approaches are well-established tools for investigating the global response of complex historic structures. Using a FE-based software package, the authors developed a numerical model of a portion of an existing historic vaulted timber structure, which is part of the roof of the Cathedral of Ica in Peru, considering the in-plane semi-rigid response of the planked arches in the elastic range. For this purpose, the rotational and shear stiffness of the joints and the properties of the materials, which are assumed in good conditions, are calibrated by comparing the numerical outputs with experimental results available in literature. The aim of the work presented here is to compare the response of the same vault assuming either continuous (planks continuously connected) or discontinuous arches (modelling of the semi-rigid response of the joints which connect the planks together).

Reconstruction of the Technical Museum in Zagreb

2013 ◽  
Vol 778 ◽  
pp. 919-926 ◽  
Author(s):  
Vlatka Rajčić ◽  
Dean Čizmar ◽  
Mislav Stepinac
Keyword(s):  
Moisture Ratio ◽  
Timber Structure ◽  
Structural Performance ◽  
Timber Structures ◽  
Large Span ◽  
Entire Structure ◽  
Structure Reconstruction ◽  
Engineering Concept

Technical Museum is one of the most visited Museums in Zagreb (capital of Croatia). The museum presents scientific and educational centre in the field of technical sciences. The entire structure of the Museum is constructed as a timber structure and as such represents a rare existing example of the European engineering concept of expo-halls timber structures with large span (85m x 40 m) from the early 20 century. In this article overview of different NDTs that were performed in order to assess the structural performance of elements is given; moisture ratio and ultrasound investigations are carried out in situ in order to investigate timber condition. Based on the detected state of the structure reconstruction measures are presented.

scholarly journals Stress-strain state of spherical shells with two unequal holes

2021 ◽  
Vol 258 ◽  
pp. 09085
Author(s):  
Nurilla Noraliev ◽  
Bakhrom Ishniyazov ◽  
Bunyod Safarov ◽  
Oybek Saparov
Keyword(s):  
Finite Element Method ◽  
Composite Materials ◽  
Stress Concentration ◽  
Software Package ◽  
Shell Thickness ◽  
Strain State ◽  
Numerical Study ◽  
Shear Stiffness ◽  
The Finite Element Method ◽  
Spherical Shells

This article presents the results of a numerical study of the stress concentration around two equal and unequal holes in an orthotropic spherical shell made of composite materials under the action of internal pressure. The influence of geometric (hole radii, shell thickness, distance between holes) characteristics, as well as material orthotropy and shear stiffness, on the stress state of spherical shells made of composite materials is studied. A numerical algorithm based on the finite element method has been developed and a software package has been implemented on a computer that allows solving the problem of stress concentration near two unequal holes in spherical shells made of composite materials.

Bending Test of the Composite Steel-Timber Beam

2013 ◽  
Vol 351-352 ◽  
pp. 415-421 ◽  
Author(s):  
Masanori Fujita ◽  
Mamoru Iwata
Keyword(s):  
Large Scale ◽  
Building Construction ◽  
Timber Structure ◽  
Bending Test ◽  
Structural Performance ◽  
Timber Structures ◽  
Timber Beam ◽  
Structural Variations ◽  
Mass Consumption ◽  
Composite Steel

In the field of building construction, mass consumption of wood materials contributes to reforestation and becomes the environmental burden reduction. However, an application to conventional timber structures only such as house has a quantitative limit. A newly developed timber structure that is able to make a large-scale building is expected. A composite steel-timber structure will be one of the effective methods to expand the structural variations. In this paper, the bending test of composite steel-timber beam classified typical joint methods is conducted to grasp basic structural performance.

scholarly journals Modelling free gas overpressure in peat layers

2020 ◽  
Vol 195 ◽  
pp. 02027
Author(s):  
Stefano Muraro ◽  
Cristina Jommi
Keyword(s):  
Unsaturated Soils ◽  
Barometric Pressure ◽  
Pressure Oscillations ◽  
Global Response ◽  
Free Gas ◽  
Soil Skeleton ◽  
Changes Over Time ◽  
Fully Coupled ◽  
Over Time ◽  
Numerical Approaches

The paper assesses fully coupled hydro-mechanical numerical approaches developed for unsaturated soils to model the effect of free gas overpressure on the response of peat layers. A simple linear model is used for the soil skeleton, however, the global response is non-linear due to changes over time of the compressibility of the solid skeleton over the compressibility of the fluid, and solubility of gas in water. The overpressure generated in foundation peat layers by barometric pressure oscillations is modelled, and the results are compared to literature data. The development of pore overpressure upon unloading is analysed as a function of the soil skeleton compressibility, and the consequences on the average stress acting on the soil skeleton are discussed.

scholarly journals Design and Structural Analysis of a SWATH type vessel using the Finite Element Method and its response to Slamming events

2020 ◽  
Vol 14 (27) ◽  
pp. 55-66
Author(s):  
Hugo Leonardo Murcia Gallo ◽  
Richard Lionel Luco Salman ◽  
David Ignacio Fuentes Montaña
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Load Condition ◽  
Structural Response ◽  
Water Area ◽  
The Finite Element Method ◽  
Short Period ◽  
Classification Society ◽  
Element Method

The main objective of this study is to analyze the structural response of a boat during a slamming event using the Finite Element Method in a Small Water Area Twin Hull (SWATH) type boat.  In the mentioned load condition, the acceptance criteria established by a classification society must be fulfilled, taking into account the areas where this event affects the structure such as the junction deck, the pontoons and other structural members established by the standard, all this generated by the high pressure loads in the ship's structure in a very short period of time being an element of study in this type of vessels, as long as they are within the range of high speed vessels. Among the main results of this study were the deformations and stresses in the structure obtained under the reference parameters of the classification society.

An On-Going Monitoring Project of a New Timber Structure

2013 ◽  
Vol 778 ◽  
pp. 757-764 ◽  
Author(s):  
Francesca Lanata
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
Construction Material ◽  
Structural Response ◽  
Timber Structures ◽  
The Real ◽  
Structural Health

Structural design, regardless of construction material, is based mainly on deterministic codes that partially take into account the real structural response under service and environmental conditions. This approach can lead to overdesigned (and expensive) structures. The differences between the designed and the real behaviors are usually due to service loads not taken into account during the design or simply to the natural degradation of materials properties with time. This is particularly true for wood, which is strongly influenced by service and environmental conditions. Structural Health Monitoring can improve the knowledge of timber structures under service conditions, provide information on material aging and follow the degradation of the overall building performance with time.A long-term monitoring control has been planned on a three-floor structure composed by wooden trusses and composite concrete-wood slabs. The structure is located in Nantes, France, and it is the new extension to the Wood Science and Technology Academy (ESB). The main purpose of the monitoring is to follow the long-term structural response from a mechanical and energetic point of view, particularly during the first few service years. Both static and dynamic behavior is being followed through strain gages and accelerometers. The measurements will be further put into relation with the environmental changes, temperature and humidity in particular, and with the operational charges with the aim to improve the comprehension of long-term performances of wooden structures under service. The goal is to propose new improved and optimized methods to make timber constructions more efficient compared to other construction materials (masonry, concrete, steel).The paper will mainly focus on the criteria used to design the architecture of the monitoring system, the parameters to measure and the sensors to install. The first analyses of the measurements will be presented at the conference to have a feedback on the performance of the installed sensors and to start to define a general protocol for the Structural Health Monitoring of such type of timber structures.

Improving the honing accuracy of the holes of stepped thin-walled cylinders

2021 ◽  
pp. 49-54
Author(s):  
V.A. Ogorodov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cutting Forces ◽  
Software Package ◽  
The Finite Element Method ◽  
Radial Forces ◽  
Thin Walled ◽  
Hole Machining ◽  
Deform 3D ◽  
Walled Cylinder

Different ways of fixing of stepped thin-walled cylinders during honing are analyzed. The conditions for increasing the accuracy of hole machining are determined on the basis of unevenness of cylinder deformations from clamping forces and radial forces simulating cutting forces. The studies used the finite element method and the DEFORM-3D V6.1 software package. Keywords: honing, stepped thin-walled cylinder, hole, accuracy, fixing method, deformation, unevenness, DEFORM-3D V6.1 software package. [email protected]

scholarly journals Calculation of radial inhomogeneity cylindrical shell when exposed to high temperatures by numerical-analytical method and fem

2019 ◽  
Vol 135 ◽  
pp. 01037
Author(s):  
Vladimir Andreev ◽  
Lyudmila Polyakova
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Method ◽  
Software Package ◽  
Successive Approximations ◽  
Method Of Successive Approximations ◽  
Infinite Cylinder ◽  
The Finite Element Method ◽  
Numerical Analytical Method ◽  
Element Method

The purpose of the work is to compare two calculation methods using the example of solving the axisymmetric thermoelasticity problem. The calculation of a thick-walled cylindrical three-layer shell on the temperature effect was carried out by the numerical-analytical method and the finite element method implemented in the LIRA-CAD software package. In the calculation, a piecewise linear inhomogeneity of the shell due to its three-layer structure and continuous inhomogeneity caused by the influence of a stationary temperature field is taken into account. The numerical-analytical method of calculation involves the derivation of a resolving differential equation, which is solved by the sweep method, it is possible to take into account the nonlinear nature of the deformation of the material using the method of successive approximations. To solve this problem by the finite element method, a similar computational model of the shell was constructed in the LIRA-CAD software package. The solution of the problem of thermoelasticity for an infinite cylinder (under conditions of a plane deformed state) and for a cylinder of finite length with free ends is given. Comparison of the calculation results is carried out according to the obtained values of ring stresses.

scholarly journals Predictive Analytics of In-Service Bridge Structural Performance from SHM Data Mining Perspective: A Case Study

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Qiwen Jin ◽  
Zheng Liu ◽  
Junchi Bin ◽  
Weixin Ren
Keyword(s):  
Data Mining ◽  
Performance Analysis ◽  
Early Warning ◽  
Predictive Analytics ◽  
Structural Response ◽  
Steel Tube ◽  
Structural Performance ◽  
Online Analysis ◽  
Analysis Methods ◽  
Load Tests

In-service bridge structural performance analysis and prediction are usually complicated and challenging because of many unknown and uncertain factors. Contrary to the traditional structural appearance inspections and load tests, structural health monitoring (SHM) can provide a perspective for online analysis, prediction, and early warning. So far, SHM has been widely used in many bridge structures, and a lot of bridge SHM data have also been collected. However, the existing studies usually focus on some independent and unsystematic analysis methods, which are hard to use widely in engineering applications to reveal the overall structural performance. This study focuses on the structural performance analysis and prediction of the highway in-service bridge. The dynamic problems in bridge SHM are pointed out firstly, followed by a detailed analysis about the characteristics of bridge SHM data. With the consideration of different characteristics, three targeted analysis methods are proposed. An urban concrete-filled steel tube (CFST) truss girder bridge (opened to traffic in 1995) is also presented, which once experienced some prominent vibration problems. The bridge SHM system is designed and stalled after several appearance inspections, load tests, and some reinforcement measures. The data mining methods proposed (distribution function, association analysis, and time-series analysis) are employed for the analysis and prediction of structural response and deterioration extent. This study can provide some references for maintenance and management and can also build a foundation for further online analysis and early warning.

scholarly journals Structural Monitoring and Safety Assessment during Translocation of Mahavira Hall of Jade Buddha Temple

2019 ◽  
Vol 11 (19) ◽  
pp. 5477 ◽  
Author(s):  
Zhang ◽  
Xue ◽  
Xie ◽  
Zhang ◽  
Lu
Keyword(s):  
Safety Assessment ◽  
Structural Integrity ◽  
Relative Displacement ◽  
Value Theory ◽  
Timber Structure ◽  
Structural Monitoring ◽  
Structural Performance ◽  
Threshold Values ◽  
Limit Value ◽  
The Ancient Chinese

The Mahavira Hall of the Jade Buddha Temple in Shanghai, China is a century-old traditional timber structure with a post-and-lintel construction. To improve the temple’s architectural layout and enhance the lintel structural integrity, the Mahavira Hall was moved 30.66 m and then elevated 1.05 m in September 2017. To assist in the structural translocation and uplift, the authors designed a monitoring system to continuously measure the relative displacement and inclination of the overall structure, individual components, and inside statues to ensure the integrity of the hall and its contents. This article presents and summarizes the priority issues and principles of monitoring the ancient Chinese timber structure. The time series of monitored data are decimated in order to minimize the fluctuation of data. The structural integrity of the Mahavira Hall was evaluated based on the inclination angle of its vital members. Finally, combined with the limit value regulated by code and the predicted early warning threshold values, which are based on extreme value theory, the effect of the translocation on the structural performance was obtained using fuzzy logic.

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