scholarly journals Computational modelling of mechanical response of glulam beams due to moisture inducted delamination

2021 ◽  
Vol 1209 (1) ◽  
pp. 012051
Author(s):  
J Pełczyński ◽  
P A Król
Keyword(s):  
Mechanical Response ◽  
Computational Simulation ◽  
Computational Modelling ◽  
Plane Stress State ◽  
Theory Of Elasticity ◽  
Point Of View ◽  
Engineering Practice ◽  
Software Environment ◽  
Typical Application ◽  
Glued Laminated Timber

Abstract Glued laminated timber beams are nowadays used as load-bearing beams of large-span structures that operate in various humidity conditions. Typical application areas are aqua parks with high humidity as well as market halls with low humidity. It is related to the possibility of the occurrence of cracks typical for the drying of wood, even with such controlled conditions of production technology as glued laminated timber. Cracks visible on the used girders raise doubts as to the safe operation of the structures. The subject of this paper is the computational simulation and the evaluation of the influence of beam delamination on the mechanical response of the structure. The attention was established on a typical two-span beam of constant height with a slight slope to the horizontal. The numerical analysis was carried out for three variants of the location of potential delamination of different scope. The beams were modeled as a problem of the linear theory of elasticity in a plane stress state with orthotropic material properties. The calculations were made in the Abaqus software environment. The results obtained in the paper allow to determine the areas in which the presence of delamination or cracks should be considered dangerous from the point of view of the safety of operation. Computational analysis is helpful in assessing the safety of structures where cracks appear. Theoretical considerations are supplemented by an example from engineering practice.

scholarly journals New Deterministic Mathematical Model for Estimating the Useful Energy Output of a Medium-Sized Solar Domestic Hot Water System

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2753
Author(s):  
Miroslaw Zukowski ◽  
Walery Jezierski
Keyword(s):  
Thermal Power ◽  
Optimization Procedure ◽  
Climatic Conditions ◽  
Point Of View ◽  
Hot Water ◽  
Energy Output ◽  
Daily Consumption ◽  
Software Environment ◽  
Optical Efficiency ◽  
Domestic Hot Water

According to the authors of this paper, the mathematical point of view allows us to see what sometimes cannot be seen from the designer’s point of view. The aim of this study was to estimate the influence of the most important parameters (volume of heat storage tanks, daily consumption of domestic hot water, optical efficiency, heat loss coefficient, and total area of a solar collector) on the thermal power output of solar domestic hot water (SDHW) system in European climatic conditions. Three deterministic mathematical models of these relationships for Madrid, Budapest, and Helsinki were created. The database for the development of these models was carried out using computer simulations made in the TRNSYS software environment. The SDHW system located at the Bialystok University of Technology (Poland) was the source of the measurement results used to validate the simulation model. The mathematical optimization procedure showed that the maximum annual useful energy output that can be obtained from 1 m2 of gross collector area is 1303 kWh in the case of Madrid, 918.5 kWh for Budapest, and 768 kWh for Helsinki weather conditions.

scholarly journals On the Finite Element Model of Rotating Functionally Graded Graphene Beams Resting on Elastic Foundation

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Nguyen Van Dung ◽  
Nguyen Chi Tho ◽  
Nguyen Manh Ha ◽  
Vu Trong Hieu
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Elastic Foundation ◽  
Mechanical Response ◽  
Shear Deformation Theory ◽  
Free Vibration Analysis ◽  
Element Model ◽  
Functionally Graded ◽  
Mode Shapes ◽  
Engineering Practice

Rotating structures can be easily encountered in engineering practice such as turbines, helicopter propellers, railroad tracks in turning positions, and so on. In such cases, it can be seen as a moving beam that rotates around a fixed axis. These structures commonly operate in hot weather; as a result, the arising temperature significantly changes their mechanical response, so studying the mechanical behavior of these structures in a temperature environment has great implications for design and use in practice. This work is the first exploration using the new shear deformation theory-type hyperbolic sine functions to carry out the free vibration analysis of the rotating functionally graded graphene beam resting on the elastic foundation taking into account the effects of both temperature and the initial geometrical imperfection. Equations for determining the fundamental frequencies as well as the vibration mode shapes of the beam are established, as mentioned, by the finite element method. The beam material is reinforced with graphene platelets (GPLs) with three types of GPL distribution ratios. The numerical results show numerous new points that have not been published before, especially the influence of the rotational speed, temperature, and material distribution on the free vibration response of the structure.

scholarly journals Cavitation Erosion and Sliding Wear of MCrAlY and NiCrMo Coatings Deposited by HVOF Thermal Spraying

2020 ◽  
Vol 20 (2) ◽  
pp. 26-38 ◽  
Author(s):  
M. Szala ◽  
M. Walczak ◽  
L. Łatka ◽  
K. Gancarczyk ◽  
D. Özkan
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Nickel Content ◽  
Thermal Spraying ◽  
Point Of View ◽  
Engineering Practice ◽  
Hvof Thermal Spraying ◽  
Cavitation Erosion Resistance

AbstractThe investigation into wear resistance is an up-to-date problem from the point of view of both scientific and engineering practice. In this study, HVOF coatings such as MCrAlY (CoNiCrAlY and NiCoCrAlY) and NiCrMo were deposited on AISI 310 (X15CrNi25-20) stainless steel substrates. The microstructural properties and surface morphology of the as-sprayed coatings were examined. Cavitation erosion tests were conducted using the vibratory method in accordance with the ASTM G32 standard. Sliding wear was examined with the use of a ball-on-disc tribometer, and friction coefficients were measured. The sliding and cavitation wear mechanisms were identified with the SEM-EDS method. In comparison to the NiCrMo coating, the MCrAlY coatings have lower wear resistance. The cavitation erosion resistance of the as-sprayed M(Co,Ni)CrAlY coatings is almost two times lower than that of the as-sprayed NiCrMoFeCo deposit. Moreover, the sliding wear resistance increases with increasing the nickel content as follows: CoNiCrAlY < NiCoCrAlY < NiCrMoFeCo. The mean friction coefficient of CoNiCrAlY coating equals of 0.873, which almost 50% exceed those reported for coating NiCrMoFeCo of 0.573. The as-sprayed NiCrMoFeCo coating presents superior sliding wear and cavitation erosion resistance to the as-sprayed MCrAlY (CoNiCrAlY and NiCoCrAlY) coatings.

scholarly journals Hotspot analysis: a first prototype Python plugin enabling exploratory spatial data analysis into QGIS

2016 ◽  
Author(s):  
Daniele Oxoli ◽  
Mayra A Zurbarán ◽  
Stanly Shaji ◽  
Arun K Muthusamy
Keyword(s):  
Data Analysis ◽  
Spatial Data ◽  
Point Of View ◽  
Geospatial Data ◽  
Spatial Data Analysis ◽  
Exploratory Spatial Data Analysis ◽  
Software Environment ◽  
Hotspot Analysis ◽  
Computational Procedures ◽  
Gis Software

The growing popularity of Free and Open Source (FOSS) GIS software is without doubts due to the possibility to build and customize geospatial applications to meet specific requirements for any users. From this point of view, QGIS is one of the most flexible as well as fashionable GIS software environment which enables users to develop powerful geospatial applications using Python. Exploiting this feature, we present here a first prototype plugin for QGIS dedicated to Hotspot analysis, one of the techniques included in the Exploratory Spatial Data Analysis (ESDA). These statistics aim to perform analysis of geospatial data when spatial autocorrelation is not neglectable and they are available inside different Python libraries, but still not integrated within the QGIS core functionalities. The main plugin features, including installation requirements and computational procedures, are described together with an example of the possible applications of the Hotspot analysis.

Effect of the Constitutive Law on the Accuracy of Prediction of the Forming Limit Curves

2012 ◽  
Vol 504-506 ◽  
pp. 77-82 ◽  
Author(s):  
Liana Paraianu ◽  
Dan Sorin Comsa ◽  
Ioan Pavel Nicodim ◽  
Ioan Ciobanu ◽  
Dorel Banabic
Keyword(s):  
Sheet Metal ◽  
Mechanical Response ◽  
Yield Criterion ◽  
Plastic Anisotropy ◽  
Equivalent Stress ◽  
Point Of View ◽  
Constitutive Law ◽  
Forming Limit ◽  
Accuracy Of Prediction ◽  
Forming Limit Curves

The accuracy of the forming limit curves predicted by the Marciniak-Kuczynski model depends on the type and flexibility of the constitutive equations used to describe the mechanical response of the sheet metal. From this point of view, the yield criterion has the most significant influence. The paper presents a comparative analysis referring to the quality of the forming limit curves predicted by the Marciniak-Kuczynski model for the case when the plastic anisotropy of a DC04 sheet metal is described by the BBC2005 yield criterion. The coefficients included in the expression of the BBC2005 equivalent stress are evaluated using different identification strategies (with 4, 6, 7, and 8 mechanical parameters). The forming limit curves predicted by the Marciniak-Kuczynski model in each of the cases previously mentioned are compared with experimental data.

Phenomenological and Structural Aspects of the Mechanical Response of Arteries

2000 ◽  
Author(s):  
Ray W. Ogden ◽  
Christian A. J. Schulze-Bauer
Keyword(s):  
Residual Stresses ◽  
Mechanical Response ◽  
Physiological State ◽  
Circumferential Stress ◽  
Morphological Structure ◽  
Cylindrical Tube ◽  
Single Layer ◽  
Theory Of Elasticity ◽  
Starting Point ◽  
Circular Cylindrical Tube

Abstract In this paper we present some new data from extension-inflation tests on a human iliac artery and then, on the basis of the nonlinear theory of elasticity, we examine a possible model to represent this data. The model considers the artery initially as a thick-walled circular cylindrical tube which may consist of two or more concentric layers. In order to take some account of the architecture (morphological structure), each layer of the material is regarded as consisting of two families of mechanically equivalent helical fibers symmetrically disposed with respect to the cylinder axis. The resulting material properties are then orthotropic in each layer. General formulas for the pressure and the axial load in the symmetric inflation of an extended tube are obtained. The starting point is the unloaded circular cylindrical configuration, but (in general unknown) residual stresses are included in the formulation. The model is illustrated by specializing firstly to the case of a single layer so that the consequences of the hypothesis of uniform circumferential stress in the physiological state can be examined theoretically. This enables the required residual stresses to be calculated explicitly. Secondly, the equations are specialized for the membrane approximation in order to show how certain important characteristics of the experimental data can be replicated using a relatively simple anisotropic membrane model.

Optimization of Trimaran Design Configuration in Calm and Deep Water

2020 ◽  
Author(s):  
Renato Skejic ◽  
Sverre A. Alterskjær
Keyword(s):  
Deep Water ◽  
Optimization Procedure ◽  
Wave Theory ◽  
Point Of View ◽  
Engineering Practice ◽  
Total Resistance ◽  
Operational Parameters ◽  
Viscous Effects ◽  
Greenhouse Gasses ◽  
Hard Particles

The field of sea based modern shipping activities is constantly seeking for its improvements to achieve the economically justified operational patterns. In the same time, the sea transportation activities also need to satisfy currently imposed and, as well as, upcoming in the near future, safety and ecologically friendly footprint characteristics when it comes to the emission of greenhouse gasses and hard particles [1]. Fulfilment of the stated requirements consequently asks for the determination of certain vessels operational parameters such as the total resistance of a vessel which estimation is frequently carried out for predefined calm and deep-water environmental scenario. Current work is dealing with investigation of the total resistance parameter in calm and deep water for the preselected types of the trimaran ship hull configurations. The total resistance is estimated according to [2] recommended procedure through applicability of the robust and reliable method which is capable to address the problem of wave resistance prediction in calm and deep water. The method has origin in ordinary and modified Michell thin – ship wave theory by considering the viscous effects [3]. The differences between the utilized theories are discussed from the qualitative and quantitative point of view of the obtained results in comparison to the open source available theoretical experimental data and from the perspective of common engineering practice. Finally, based on the above description, the performed total resistance studies are used as a base for formulation of the optimization procedure which may be used in the trimaran vessel preliminary designs in the range of the forward speeds commonly expected during the normal operational life of the investigated trimaran vessel.

scholarly journals On the Effects of Structural Coupling on Piezoelectric Energy Harvesting Systems Subject to Random Base Excitation

Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 93
Author(s):  
Hamidreza Masoumi ◽  
Hamid Moeenfard ◽  
Hamed Haddad Khodaparast ◽  
Michael I. Friswell
Keyword(s):  
Energy Harvesting ◽  
Mechanical Response ◽  
Harmonic Excitation ◽  
Point Of View ◽  
Analytical Models ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Novel Approach ◽  
Band Limited ◽  
Multi Body

The current research investigates the novel approach of coupling separate energy harvesters in order to scavenge more power from a stochastic point of view. To this end, a multi-body system composed of two cantilever harvesters with two identical piezoelectric patches is considered. The beams are interconnected through a linear spring. Assuming a stochastic band limited white noise excitation of the base, the statistical properties of the mechanical response and those of the generated voltages are derived in closed form. Moreover, analytical models are derived for the expected value of the total harvested energy. In order to maximize the expected generated power, an optimization is performed to determine the optimum physical and geometrical characteristics of the system. It is observed that by properly tuning the harvester parameters, the energy harvesting performance of the structure is remarkably improved. Furthermore, using an optimized energy harvester model, this study shows that the coupling of the beams negatively affects the scavenged power, contrary to the effect previously demonstrated for harvesters under harmonic excitation. The qualitative and quantitative knowledge resulting from this analysis can be effectively employed for the realistic design and modelling of coupled multi-body structures under stochastic excitations.

Managing Enterprise Architecture Change

2007 ◽  
pp. 192-205 ◽  
Author(s):  
T. O’Neill ◽  
M. Denford ◽  
J. Leaney ◽  
K. Dunsire
Keyword(s):  
Enterprise Architecture ◽  
Point Of View ◽  
Emergent Properties ◽  
Engineering Practice ◽  
Top Down ◽  
Systems Architecture ◽  
Architectural Model ◽  
Complex Architectures ◽  
Computer Based ◽  
And Control

Enterprise architecture (EA) is the recognised place where the engineering practice of systems architecture meets real-world enterprise needs. The enterprise computer-based systems employed by organisations today can be extremely complex. These systems are essential for undertaking business and general operations in the modern environment, and yet the ability of organisations to control their evolution is questionable. The emerging practice of enterprise architecture seeks to control that complexity through the use of a holistic and top-down perspective. However, the methodologies and toolsets already in use are very much bottom-up by nature. An architecture-based approach is herein proposed; one that has at its base a complete and formal architectural description (or model). This allows enterprise architects, strategists, and designers to confidently model, predict, and control the emergent properties of their respective systems from an architectural point of view. The authors conclude that by using an approach founded upon an architectural model to analyse software and enterprise systems, architects can guide the design and evolution of architectures based on quantifiable nonfunctional requirements. Furthermore, hierarchical 3D visualisation provides a meaningful and intuitive means for conceiving and communicating complex architectures.

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