Influence of interior layer properties to moisture dry-out of CLT walls

2019 ◽  
Vol 46 (11) ◽  
pp. 1001-1009 ◽  
Author(s):  
Villu Kukk ◽  
Annegrete Külaots ◽  
Jaan Kers ◽  
Targo Kalamees
Keyword(s):  
Moisture Content ◽  
Laboratory Test ◽  
Simulation Model ◽  
Initial Moisture Content ◽  
Mineral Wool ◽  
Test Results ◽  
Interior Layer ◽  
Cross Laminated Timber ◽  
Simulation Results ◽  
Dry Out

The objective of this study was to determine the maximum allowable initial moisture content (MC) for cross-laminated timber (CLT) walls having both exterior and interior thermal insulation. A laboratory test was conducted, for which four test walls with two different insulation solutions and two different MCs were built. Based on the test results, a simulation model was configured and simulations using the model were completed. The simulation results determined that the maximum allowable initial MC of the CLT panels was 17% for walls insulated additionally from inside with mineral wool and 15% for CLT wall assemblies insulated with polyisocyanurate (PIR). Based on these results, it was concluded that the allowable MC ranges between 8% and 16% for construction timber, and therefore, using a PIR board as interior insulation for CLT walls should be undertaken with caution given the very small margin for error in MC.

scholarly journals Influence of Freeze-Thaw Cycles on Mechanical Response of Levee Pavement

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shuan Guo ◽  
Zheng Lu ◽  
Guokun Liu ◽  
Baoli Zhuang ◽  
Yongfeng Fan ◽  
...  
Keyword(s):  
Moisture Content ◽  
Mechanical Response ◽  
Triaxial Compression ◽  
Initial Moisture Content ◽  
Dry Density ◽  
Test Results ◽  
Freeze Thaw ◽  
Temperature Range ◽  
Pavement Structure ◽  
The Stability

The freeze-thaw cycles cause deterioration in mechanical properties of levee soil and further endanger the pavement structure on the embankment. This study attempts to comprehensively understand the mechanical response of pavement after freeze-thaw cycles. In this paper, the freeze-thaw cycles test under an open system was carried out, and then the triaxial compression test was conducted. Based on the test results, the effects of freeze-thaw cycles, temperature range, initial dry density, and initial moisture content of embankment soil on the mechanical response of road structure after freeze-thaw were calculated and analyzed. Finally, the stability of the slope of the levee was evaluated. The results show that the number of freeze-thaw cycles has the most significant impact on the mechanical response of pavement, the stress and strain of the structural layers vary in different ranges, and the pavement deflection increases by 5 times after 7 freeze-thaw cycles. However, the initial dry density and initial moisture content of the soil have little influence on the pavement structure, and the temperature range will exert an influence when it exceeds a certain threshold.

Analysis of Dynamic Characteristics of Automatic Transmission Shifting Control

2014 ◽  
Vol 643 ◽  
pp. 42-47 ◽  
Author(s):  
Yan Xiao Fu ◽  
Liang Yi Cui ◽  
Xiang Yang Xu ◽  
Peng Dong
Keyword(s):  
Simulation Model ◽  
Control Strategy ◽  
Model Simulation ◽  
Automatic Transmission ◽  
Test Results ◽  
Shift Quality ◽  
Impact Function ◽  
Automatic Transmissions ◽  
Simulation Results ◽  
The Impact

Basing on the fact that requirements for shift quality in automatic transmissions have been increasing rapidly necessitates the establishment of a suitable shifting control strategy in order to facilitate smoothness of different processes, this paper introduces a simulation model of an 8-speed automatic transmission for front-drive vehicles with respect to detailed shifting strategies and relative parameters. The transmitted torque of the oncoming shift elements before synchronization point can be reduced by an impact function in order to damp the impact and thus make the gear shifting process more smooth. This paper makes a systematic introduction of the structure of 8AT, theoretical basis of control strategy, the establishment of the simulation model and the comparison between test results and simulation results. The conclusion shows that with an accurate dynamic model, simulation results and test results are neighborhood data, the simulation model can be used to help realizing the ultimate goal of better shift quality with higher efficiency, lower shift loads and improved shifting comfort.

scholarly journals Research on Modeling and Simulation of Electro Backup Hydraulic Actuation System

2020 ◽  
Vol 179 ◽  
pp. 01014
Author(s):  
Pei Lei ◽  
Hongjun Pang ◽  
Sa Liu
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
System Performance ◽  
Test Results ◽  
Sweep Frequency ◽  
Actuation System ◽  
Working Principle ◽  
Simulation Results ◽  
System Characteristics ◽  
Application Prospects

As one form in power-by-wire actuation system, the Electro backup hydraulic actuation system (EBHAs) has broad application prospects in the aviation field. In this paper, a numerical simulation model of the system performance for EBHAs is established. Based on the detailed description of its working principle, the mathematical models of EBHAs and its subsystems, as well as numerical model in the Matlab / Simulink environment are established, and a larger number of numerical simulations are carried out, which contain the normal working mode and the backup working mode. Furthermore, numerical simulation results are compared and analyzed with those results of experimental, which further verified the system simulation model established in this paper. It can be concluded from the results that the dynamic response of the system can meet the requirements of the design, no matter the normal or backup working modes. And the simulation results of the system sweep frequency are basically consistent with the test results, and the error is less than 10%. It is clear that the simulation model presented in this paper can accurately describe the system characteristics of EBHAs, which is useful to the design of EBHAs system.

Numerical Impact Simulation of Aircraft Into Reinforced Concrete Walls With Different Thickness

2018 ◽  
Author(s):  
Kazuma Hirosaka ◽  
Hidekazu Takazawa ◽  
Katsumasa Miyazaki ◽  
Norihide Tohyama ◽  
Hiroyuki Nouji ◽  
...  
Keyword(s):  
Experimental Data ◽  
Simulation Model ◽  
Impact Analysis ◽  
Impact Test ◽  
Test Results ◽  
Physical Damage ◽  
Concrete Wall ◽  
Concrete Walls ◽  
Simulation Results ◽  
The Relationship

Aircraft impact analysis is needed for a safety assessment of nuclear power plants. One of the contents which should be analysed for aircraft impact is physical damage of a concrete building and this can be estimated by a numerical simulation. In order to conduct aircraft impact analysis, simulation model which validated by some experimental data needs to be established. In 1990s, impact test using actual F4 Phantom fighter was conducted at Sandia national laboratory in U.S. and a lot of important experimental data were measured. In this paper, the numerical simulation results for this F4 Phantom impact test are introduced. The relationship between the thickness of the shell of the F4 Phantom simulation model and the deceleration of this model is indicated and the differences of the deceleration between simulation and test results are discussed. In addition, the relationship between fracture strain of the shell of the F4 Phantom simulation model and the destruction mode of this model in simulation is indicated and the differences between the destruction mode of the F4 Phantom between simulation and test results are discussed. In order to evaluate the physical damage area after the aircraft impact, it is necessary to estimate the aircraft velocity after it perforates the outer concrete wall and to calculate the decrease of the kinematic energy of the aircraft by this perforation. In this paper, several aircraft impact simulations with different concrete wall thickness are conducted and the reduction in kinematic energies of an aircraft by a perforation is estimated. Using these simulation results, the necessary numbers of concrete walls until the impacting aircraft stops is discussed.

scholarly journals Modeling the Drying of Capillary-Porous Materials in a Thin Layer: Application to the Estimation of Moisture Content in Thin-Walled Building Blocks

2020 ◽  
Vol 10 (19) ◽  
pp. 6953
Author(s):  
Gennadiy Kolesnikov ◽  
Timmo Gavrilov
Keyword(s):  
Moisture Content ◽  
Porous Materials ◽  
Initial Moisture Content ◽  
Building Blocks ◽  
Analytical Relationship ◽  
Drying Process ◽  
Drying Temperature ◽  
Ceramic Blocks ◽  
Thin Walled ◽  
Simulation Results

Drying, as a process of changing the moisture content and temperature of capillary-porous materials, is a necessary step in many technologies. When predicting moisture changes, it is necessary to find a balance between the complexity of a model and the accuracy of the simulation results. The purpose of this work was the development of a mathematical model for drying a capillary-porous material with direct consideration of its initial moisture content and drying temperature. Methods of mathematical modeling were used in the work. Using the developed model, an analysis of the features of the drying process of materials with high and low initial moisture content has been carried out. The analytical relationship for determining the time at which the extremum of the drying rate is reached has been substantiated. A model has been developed to directly take into account the influence of the initial material moisture content and drying temperature. The simulation results are consistent with the experiments on drying ceramic blocks for construction which are described in the literature. The obtained results can be taken into account in studies of the effect of drying modes on the energy consumption of a drying process.

Examination of Tobacco Hygroscopicity / Über die Hygroskopizität des Tabaks

1965 ◽  
Vol 3 (1) ◽  
Author(s):  
L. Hübschen
Keyword(s):  
Moisture Content ◽  
Sorption Isotherm ◽  
Initial Moisture Content

AbstractThe present paper shows the detectable factors on which a sorption isotherm depends. Even if it is well-known that a sorption isotherm is most essentially conditioned by influences of the respective tobacco variety, other factors, such as temperature, initial moisture content, or fibre dimension, play a part as well. In general, a sorption isotherm constitutes a ''summation'' of such factors and, in the end, a combination of desorption and adsorption if the tobacco is dried or moistened from the average commercial moisture content. The tobacco hysteresis is experimentally investigated and discussed

Pengeringan Biji Kakao dengan Pengering Surya Tipe Terowong Berpenggerak Sel Fotovoltaik di Manokwari

Agrotek ◽  
2018 ◽  
Vol 2 (6) ◽  
Author(s):  
Wilson Palelingan Aman
Keyword(s):  
Moisture Content ◽  
Performance Test ◽  
Initial Moisture Content ◽  
Maximum Temperature ◽  
Photovoltaic Module ◽  
Cocoa Beans ◽  
Drying Time ◽  
Tunnel Dryer ◽  
Heat Collector ◽  
New Construction

<em>A research about cocoa beans drying used solar tunnel dryer with photovoltaic module driven have conducted in Manokwari. Solar tunnel dryer used in this research adapted from type Hohenheim with photovoltaic module and integrated air heat collector has been installed at the Department of Agricultural Technology, Papua State University Manokwari to dried cocoa beans. The objectives of this research were to design solar tunnel dryer and evaluate it�s performance in dryed cocoa beans. The result obtained was a new construction of solar tunnel dryer for cocoa beans with dimensions 6 m of length and 0,9 m of wide. The dryer completed with photovoltaic module to drive the blowers of hot drying air. �Performance test of the dryer showed that drying of 10 kg of cocoa beans with initial moisture content about 70% wet basis needed 13 hours of drying time to achieved final moisture content about 7,17% wet basis. The drying time achieved was faster compared than traditional solar drying that needed 20 hours of drying time. The maximum temperature achieved in drying chamber was 60 <sup>o</sup>C.</em>

scholarly journals Wood Chip Drying through the Using of a Mobile Rotary Dryer

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1590 ◽  
Author(s):  
Angelo Del Giudice ◽  
Andrea Acampora ◽  
Enrico Santangelo ◽  
Luigi Pari ◽  
Simone Bergonzoli ◽  
...  
Keyword(s):  
Moisture Content ◽  
Power Plants ◽  
Black Locust ◽  
Thermal Power ◽  
Initial Moisture Content ◽  
Wood Chip ◽  
Wood Chips ◽  
Cocurrent Flow ◽  
Drying Process ◽  
Rotary Dryer

Drying is a critical point for the exploitation of biomass for energy production. High moisture content negatively affects the efficiency of power generation in combustion and gasification systems. Different types of dryers are available however; it is known that rotary dryers have low cost of maintenance and consume 15% and 30% less in terms of specific energy. The study analyzed the drying process of woody residues using a new prototype of mobile rotary dryer cocurrent flow. Woodchip of poplar (Populus spp.), black locust (Robinia pseudoacacia L.), and grapevine (Vitis vinifera L.) pruning were dried in a rotary drier. The drying cycle lasted 8 h for poplar, 6 h for black locust, and 6 h for pruning of grapevine. The initial biomass had a moisture content of around 50% for the poplar and around 30% for grapevine and black locust. The study showed that some characteristics of the biomass (e.g., initial moisture content, particle size distribution, bulk density) influence the technical parameters (i.e., airflow temperature, rate, and speed) of the drying process and, hence, the energy demand. At the end of the drying process, 17% of water was removed for poplar wood chips and 31% for grapevine and black locust wood chips. To achieve this, result the three-biomass required 1.61 (poplar), 0.86 (grapevine), and 1.12 MJ kgdry solids−1 (black locust), with an efficiency of thermal drying (η) respectively of 37%, 12%, and 27%. In the future, the results obtained suggest an increase in the efficiency of the thermal insulation of the mobile dryer, and the application of the mobile dryer in a small farm, for the recovery of exhaust gases from thermal power plants.

Effect of Ibuprofen on Serum Laboratory Test Results

1983 ◽  
Vol 40 (6) ◽  
pp. 1025-1034
Author(s):  
Carol L. Colvin ◽  
Raymond J. Townsend ◽  
William R. Gillespie ◽  
Kenneth S. Albert
Keyword(s):  
Laboratory Test ◽  
Test Results ◽  
Laboratory Test Results
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