scholarly journals Behavioral Assessment and Evaluation of Innovative Hollow Glue-Laminated Timber Elements

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6911
Author(s):  
Nikola Perković ◽  
Vlatka Rajčić ◽  
Monika Pranjić
Keyword(s):  
Mechanical Performance ◽  
Behavioral Assessment ◽  
Modular Construction ◽  
The Finite Element Method ◽  
Construction Time ◽  
Modular Systems ◽  
Assessment And Evaluation ◽  
Construction Machinery ◽  
Absorbing Material ◽  
And Behavior

Due to the growing need to preserve our planet and reduce carbon emissions during construction, the use of the only carbon-absorbing material, timber, is increasingly being imposed. In addition to the requirement of reducing emissions, there is a necessity for the shortest possible construction time and the minimum use of construction machinery, which has led to the development of prefabricated construction systems. This paper deals with the innovative, hollow, glue-laminated timber elements which are intended for modular construction. Comparing this new system with existing modular systems, the main features and behavior of the constitutive elements, i.e., the hollow, glue-laminated timber elements, are presented. Experimental and numerical analysis of the mechanical performance of the timber elements was carried out and a comparative analysis of the behavior of two different types of hollow timber elements was conducted. The finite element method was used to predict the behavior of this innovative structural system. The results are compared with the analytical procedure to provide a background for the development of standardized methods for the design of timber structures.

scholarly journals Integrated Management Software for Factory Production of Modular Buildings

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
SungHoon Nam ◽  
DooYong Lee ◽  
BongHo Cho ◽  
KyungRai Kim
Keyword(s):  
Management System ◽  
Production Management ◽  
Integrated Management ◽  
Formal System ◽  
Modular Construction ◽  
Construction Time ◽  
Modular Systems ◽  
Production Management System ◽  
Modular Production ◽  
Result Analysis

After the first modular construction project in Korea in 2003, the scope and demand for modular systems have gradually increased. However, modular producers in Korea utilize spreadsheets to manage the process, manpower, and materials required for modular construction. This is inadequate compared to other countries that are more advanced in modular construction such as Japan and the United Kingdom. The management system in Korea decreases the effectiveness of modular construction in reducing construction time and cost. There is no formal system for managing modular production in Korea. Although some construction management programs utilized in the traditional construction industry are available, they do not reflect the flow of modular production, that is, to simultaneously produce several types of modules in accordance with demand in a factory. This research develops a modular-construction-specific production management system that has three overall functions: factory setup, project creation, and result analysis. These functions can link all the relevant data for managing modular production and can help manage several types of modules. The production management system is verified through simulation of the existing processes observed for a completed project and comparing the results to an alternative process. Through such comparisons, an optimized process design can be achieved.

Lateral Load Performance of Panelized Wood I-Joist Floor Systems

2020 ◽  
Vol 70 (4) ◽  
pp. 428-438
Author(s):  
Sigong Zhang ◽  
Ying Hei Chui ◽  
David Joo
Keyword(s):  
Load Transfer ◽  
Mechanical Performance ◽  
Small Scale ◽  
Construction Time ◽  
Plane Shear ◽  
Floor Systems ◽  
Diaphragm Action ◽  
Wood Frame ◽  
Strength And Stiffness ◽  
Frame Construction

Abstract Panelized light wood frame construction is becoming more popular due to the faster construction time and shortage of onsite skilled labor. To use light wood frame panels effectively in panelized floor systems, panel-to-panel joints must be fastened adequately to allow load transfer between panels. They must also possess in-plane shear strength and stiffness comparable to stick-built, staggered-sheathed assemblies. This study was designed to develop efficient and effective panel-to-panel joints for connecting adjacent floor panels built with wood I-joists and evaluate the efficiency of the joints in achieving diaphragm action. At first, a number of these panel-to-panel joints were tested in the laboratory using a small-scale diaphragm test setup to determine their efficiency in transferring in-plane forces between panels. Test results showed that a small decrease in in-plane stiffness was expected for the most effective joints, but their strengths were significantly higher than at the same location in a conventional site-built floor diaphragm. The presence of blockings and use of two-row nailing were found to considerably improve stiffness and strength. These features can be used to mitigate the potential reduction in mechanical performance of panelized floor construction, in comparison with the site-built wood I-joist floor.

scholarly journals Impact of Hydrophobic Pollutants' Behavior on Occupational and Environmental Health

2005 ◽  
Vol 5 ◽  
pp. 211-220 ◽  
Author(s):  
Ijeoma Kanu ◽  
Ebere Anyanwu
Keyword(s):  
Environmental Health ◽  
Environmental Hazards ◽  
Environmental Hazard ◽  
Assessment And Evaluation ◽  
Risk Effects ◽  
Hydrophobic Pollutants ◽  
Hazard And Risk ◽  
The Media ◽  
And Behavior

This paper reviews the influence of hydrophobic pollutant behavior on environmental hazards and risks. The definition and examples of hydrophobic pollutants are given as a guide to better understand the sources of release and the media of dispersion in the environment. The properties and behavior of hydrophobic pollutants are described and their influence on environmental hazard and risk is reviewed and evaluated. The overall outcome of the assessment and evaluation showed that all hydrophobic pollutants are hazardous and risky to all organisms, including man. Their risk effects are due to their inherent persistence, bioaccumulation potential, environmental mobility, and reactivity. Their hazardous effects on organisms occur at varying spatial and temporal degrees of emissions, toxicities, exposures, and concentrations.

scholarly journals Thermo-hydraulic Simulation of AP1000 Nuclear Reactor Fuel Assembly

2021 ◽  
Vol 31 (1) ◽  
pp. 60-71
Author(s):  
Leonardo Acosta Martínez ◽  
Carlos Rafael García Hernández ◽  
Jesus Rosales García ◽  
Annie Ortiz Puentes
Keyword(s):  
Fuel Assembly ◽  
Power Distribution ◽  
Capital Investment ◽  
Nuclear Power ◽  
Nuclear Reactor ◽  
Geometric Model ◽  
Modular Construction ◽  
Construction Time ◽  
Hydraulic Simulation ◽  
In Series

One of the challenges of future nuclear power is the development of safer and more efficient nuclear reactor designs. The AP1000 reactor based on the PWR concept of generation III + has several advantages, which can be summarized as: a modular construction, which facilitates its manufacture in series reducing the total construction time, simplification of the different systems, reduction of the initial capital investment and improvement of safety through the implementation of passive emergency systems. Being a novel design it is important to study the thermohydraulic behavior of the core applying the most modern tools. To determine the thermohydraulic behavior of a typical AP1000 fuel assembly, a computational model based on CFD was developed. A coupled neutronic-thermohydraulic calculation was performed, allowing to obtain the axial power distribution in the typical fuel assembly. The geometric model built used the certified dimensions for this type of installation that appear in the corresponding manuals. The thermohydraulic study used the CFD-based program ANSYS-CFX, considering an eighth of the fuel assembly. The neutronic calculation was performed with the program MCNPX version 2.6e. The work shows the results that illustrate the behavior of the temperature and the heat transfer in different zones of the fuel assembly. The results obtained agree with the data reported in the literature, which allowed the verification of the consistency of the developed model.

scholarly journals ASSESSMENT OF THE STRENGTH OF A COMPOSITE PACKAGE WITH INTERNAL DEFECTS ACCORDING TO VARIOUS FAILURES CRITERIA UNDER THE INFLUENCE OF UNSTEADY LOAD

2020 ◽  
Vol 17 (35) ◽  
pp. 1218-1230
Author(s):  
Aleksandr L. MEDVEDSKIY ◽  
Mikhail I. MARTIROSOV ◽  
Anton V. KHOMCHENKO ◽  
Darina V. DEDOVA
Keyword(s):  
Polymer Composite ◽  
Longitudinal Direction ◽  
Polymer Composite Material ◽  
Aviation Industry ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Fracture Criteria ◽  
Safety Factors ◽  
Elliptical Shape ◽  
And Behavior

One of the priority tasks of the modern aviation industry is to increase the economic efficiency of aircrafts. In the context of solving this problem, when creating new aircrafts, polymer composite materials (PCM) are increasingly used. Particular attention is paid to structural elements, damage to which can lead to a decrease in the strength of an airframe as a whole. Therefore, an essential task in the design, maintenance, and operation of the test is to study the effect of interlayer defects on the strength and behavior of PCM structures under the influence of unsteady loads. This work is devoted to a numerical analysis of the behavior of a plate made of a polymer composite material (PCM) under unsteady load considering interlayer defects of an elliptical shape, as well as an assessment of the strength of a composite package according to various fracture criteria. The problem is solved by the finite element method using the LS-DYNA software package. Then, using the method of mathematical modeling, the interlayer separation of an elliptical shape was analyzed, which allowed to evaluate the strength of the plate and fiber according to the criteria of Hashin, Puck, Chang-Chang, and LaRC03 and compare the results. It was found in the study, that the failure indices and safety factors, which were obtained using various criteria (Hashin and Chang-Chang), have the same distribution, since the dependence of the implemented fracture mode (fiber compression in the longitudinal direction) is identical. Analysis.

scholarly journals A Study on the Effect of Carbon Nanotubes’ Distribution and Agglomeration in the Free Vibration of Nanocomposite Plates

2020 ◽  
Vol 6 (4) ◽  
pp. 79
Author(s):  
D. S. Craveiro ◽  
M. A. R. Loja
Keyword(s):  
Carbon Nanotubes ◽  
Elastic Properties ◽  
Natural Frequencies ◽  
Mechanical Performance ◽  
Negative Impact ◽  
Free Vibrations ◽  
Mode Shapes ◽  
The Finite Element Method ◽  
Agglomeration Effect ◽  
Performance Predictions

The present work aimed to characterize the free vibrations’ behaviour of nanocomposite plates obtained by incorporating graded distributions of carbon nanotubes (CNTs) in a polymeric matrix, considering the carbon nanotubes’ agglomeration effect. This effect is known to degrade material properties, therefore being important to predict the consequences it may bring to structures’ mechanical performance. To this purpose, the elastic properties’ estimation is performed according to the two-parameter agglomeration model based on the Eshelby–Mori–Tanaka approach for randomly dispersed nano-inclusions. This approach is implemented in association with the finite element method to determine the natural frequencies and corresponding mode shapes. Three main agglomeration cases were considered, namely, agglomeration absence, complete agglomeration, and partial agglomeration. The results show that the agglomeration effect has a negative impact on the natural frequencies of the plates, regardless the CNTs’ distribution considered. For the corresponding vibrations’ mode shapes, the agglomeration effect was shown in most cases not to have a significant impact, except for two of the cases studied: for a square plate and a rectangular plate with symmetrical and unsymmetrical CNTs’ distribution, respectively. Globally, the results confirm that not accounting for the nanotubes’ agglomeration effect may lead to less accurate elastic properties and less structures’ performance predictions.

scholarly journals Backbone cup – a structure design competition based on topology optimization and 3D printing

2016 ◽  
Vol 7 ◽  
pp. A1 ◽  
Author(s):  
Ji-Hong Zhu ◽  
Kai-Ke Yang ◽  
Wei-Hong Zhang
Keyword(s):  
Topology Optimization ◽  
3D Printing ◽  
Experimental Approach ◽  
Mechanical Performance ◽  
Turnaround Time ◽  
Structure Design ◽  
The Finite Element Method ◽  
New Approach ◽  
Design Competition ◽  
Testing Approach

This paper addresses a structure design competition based on topology optimization and 3D Printing, and proposes an experimental approach to efficiently and quickly measure the mechanical performance of the structures designed using topology optimization. Since the topology optimized structure designs are prone to be geometrically complex, it is extremely inconvenient to fabricate these designs with traditional machining. In this study, we not only fabricated the topology optimized structure designs using one kind of 3D Printing technology known as stereolithography (SLA), but also tested the mechanical performance of the produced prototype parts. The finite element method is used to analyze the structure responses, and the consistent results of the numerical simulations and structure experiments prove the validity of this new structure testing approach. This new approach will not only provide a rapid access to topology optimized structure designs verifying, but also cut the turnaround time of structure design significantly.

Design and performance analysis of a novel PM assisted synchronous reluctance machine

2021 ◽  
pp. 1-10
Author(s):  
Shaopeng Wang ◽  
Jinguang Ma ◽  
Chengcheng Liu ◽  
Youhua Wang ◽  
Gang Lei ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Rolling Direction ◽  
Silicon Steel ◽  
Design Parameters ◽  
Maximum Speed ◽  
The Novel ◽  
The Finite Element Method ◽  
Reluctance Machine ◽  
And Performance ◽  
Two Machines

This paper proposes a novel permanent magnet assisted synchronous reluctance (PMAREL) machine, the main structure of this machine is quite similar to that of traditional PMAREL machine, and the main difference is that the grain-oriented silicon steel is used to replace some part of the stator teeth. The rolling direction of the grain-oriented silicon steel is along the radial direction of the machine, thus the advantage of higher permeability and higher kneel point in this material can be used to release the flux saturation problem of the traditional non-grain-oriented steel used in the PMAREL machine when the applied current density is high. Firstly, the structure of both proposed novel and traditional PMAREL machines are optimized and the design parameters are determined. Secondly the electromagnetic and mechanical performance are compared in these two machines which includes the demagnetization analysis, mechanical stress analysis when the rotor at the maximum speed, torque ability, efficiency by using the finite element method (FEM). It can be seen that the problem of stator teeth saturation in the novel PMAREL has been alleviated, and compared with the traditional PMAREL machine, the novel PMAREL has higher efficiency, wider speed range and 7% higher torque ability.

Fire Protection Design for Steel Staggered-Truss Framing System Based on Mechanical Performance Calculation

2010 ◽  
Vol 97-101 ◽  
pp. 3663-3666 ◽  
Author(s):  
Chang Kun Chen ◽  
Wei Zhang ◽  
Dong Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Fire Protection ◽  
Mechanical Performance ◽  
The Finite Element Method ◽  
Protection Strategy ◽  
Plastic Process ◽  
Fire Resistance Rating ◽  
Performance Calculation ◽  
Resistance Rating

An optimizing strategy, based on the performance calculation of mechanical properties under high temperature, was proposed to study the method of fire protection design for steel staggered-truss framing system (SSTFS). That is, the whole elastic-plastic process of the structure is investigated using the finite element method firstly, and the components which appear plastic deformation easily are found, and then their fire resistance rating would be enhanced especially. In comparison with the traditional regular fire protection strategy, it is confirmed that the fire resistant capacity of the SSTFS can be improved dramatically. And the security of the structure could be ensured, while the required volume of fire protection coatings is reduced.

scholarly journals Population Status of Tapanuli Orangutan (Pongo tapanuliensis) within the Renewable Energy Development and its Management Implications

2021 ◽  
pp. 478-493
Author(s):  
Didik Prasetyo ◽  
Yokyok Hadiprakarsa ◽  
Wanda Kuswanda ◽  
Jito Sugardjito
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Forest Conversion ◽  
Suitable Habitat ◽  
Construction Time ◽  
Species Survival ◽  
Project Construction ◽  
And Behavior ◽  
Time Frames ◽  
The Impact

To protect Tapanuli orangutan it is essential to understand the actual situation. It has been studied 15% of its population live outside the protected area facing a density disruption due to forest conversion. Several best management practices have been created and tested for different natural concession types. Yet, the main objective to reduce the impact and increase wildlife survival is far away from the goal. To improve our understanding of the species survival within ongoing project construction, we conducted population density monitoring prior- to post-construction time frames within the hydroelectric dam project. Also, we carried out spatial analysis to understand the land cover change and orangutan’s suitable habitat distribution. This study found that during high construction activities, orangutans were avoiding the threat sources, and returned when the disturbances reduced. These findings indicated orangutans are ecology flexible and have the capability to increase its survival, although the company’s involvement is crucial to facilitate the successes. Our study is based on indirect observation, and spatial modeling, which may lead to an uncertain conclusion. Further research on orangutan ecology and behavior is prioritized.

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