An Investigation into the Design Parameters of Double Layer Space Frame Grids

1987 ◽  
Vol 2 (4) ◽  
pp. 215-222 ◽  
Author(s):  
Usama Rustom Madi
Keyword(s):  
Double Layer ◽  
Parametric Study ◽  
Design Parameters ◽  
Space Frame ◽  
Factors Affecting ◽  
Design Requirements

A parametric study of the various factors affecting the design of double layer space frame grids is presented. This parametric study was conducted with the help of example structures and covered the support arrangement, the grid depth, the grid module and the grid layouts. The intent is to give the designer an idea about the effects of the choice of any of these parameters on the grid's behaviour and design requirements. This information should serve as a means for developing successful preliminary designs and as such reduce the need for many trials before the design is finalised.

scholarly journals Effectiveness of Different Connectors Used in DLGs

10.29007/dksw ◽  
2018 ◽  
Author(s):  
Mansi Mehta ◽  
Dipali Patel ◽  
Vishal A. Arekar
Keyword(s):  
Double Layer ◽  
Parametric Study ◽  
Three Dimensional ◽  
Total Weight ◽  
Frame Structure ◽  
Space Frame ◽  
Static Loads ◽  
Large Span ◽  
Varying Thickness ◽  
Space Frame Structure

Double-Layer Grid structures are three-dimensional pin-jointed structures, which are generally used for covering roofs having large span areas with the help of connectors. A Double Layer Grid structures are quite popular as the use of material can be reduced, easy to assemble and permits quicker construction. The weight of the structure depends on the member as well as connectors. The connectors contain 20-30% of total weight (by referring Lan, T.T. “Space frame structure”). In present study, two types of Connectors are used for analysis and for optimisation of structure. The aim of this study is to optimize the design and to get the effective connector. Solid connector and Hollow connector (with varying thickness) have been taken for parametric study, modelled in CREO and analysed using ANSYS 17.2. The results of stresses have been obtained under the static loads for comparison.

Green roof hydrologic performance and modeling: a review

2013 ◽  
Vol 69 (4) ◽  
pp. 727-738 ◽  
Author(s):  
Yanling Li ◽  
Roger W. Babcock
Keyword(s):  
Peak Flow ◽  
Green Roof ◽  
Field Measurements ◽  
Green Roofs ◽  
Economic Benefits ◽  
Design Parameters ◽  
Technical Literature ◽  
Factors Affecting ◽  
Model Soil ◽  
Runoff Volume

Green roofs reduce runoff from impervious surfaces in urban development. This paper reviews the technical literature on green roof hydrology. Laboratory experiments and field measurements have shown that green roofs can reduce stormwater runoff volume by 30 to 86%, reduce peak flow rate by 22 to 93% and delay the peak flow by 0 to 30 min and thereby decrease pollution, flooding and erosion during precipitation events. However, the effectiveness can vary substantially due to design characteristics making performance predictions difficult. Evaluation of the most recently published study findings indicates that the major factors affecting green roof hydrology are precipitation volume, precipitation dynamics, antecedent conditions, growth medium, plant species, and roof slope. This paper also evaluates the computer models commonly used to simulate hydrologic processes for green roofs, including stormwater management model, soil water atmosphere and plant, SWMS-2D, HYDRUS, and other models that are shown to be effective for predicting precipitation response and economic benefits. The review findings indicate that green roofs are effective for reduction of runoff volume and peak flow, and delay of peak flow, however, no tool or model is available to predict expected performance for any given anticipated system based on design parameters that directly affect green roof hydrology.

A Parametric Examination of the Factors Affecting the Performance of a Diffusion Absorption Refrigeration System

2021 ◽  
pp. 1-38
Author(s):  
Noman Yousuf ◽  
Timothy Anderson ◽  
Roy Nates
Keyword(s):  
Waste Heat ◽  
Operating Conditions ◽  
Design Parameters ◽  
Working Fluid ◽  
Low Grade ◽  
Absorption Refrigeration ◽  
Factors Affecting ◽  
Thermally Driven ◽  
Mass Flowrate ◽  
Diffusion Absorption

Abstract Despite being identified nearly a century ago, the diffusion absorption refrigeration (DAR) cycle has received relatively little attention. One of the strongest attractions of the DAR cycle lies in the fact that it is thermally driven and does not require high value work. This makes it a prime candidate for harnessing low grade heat from solar collectors, or the waste heat from stationary generators, to produce cooling. However, to realize the benefits of the DAR cycle, there is a need to develop an improved understanding of how design parameters influence its performance. In this vein, this work developed a new parametric model that can be used to examine the performance of the DAR cycle for a range of operating conditions. The results showed that the cycle's performance was particularly sensitive to several factors: the rate of heat added and the temperature of the generator, the effectiveness of the gas and solution heat exchangers, the mass flowrate of the refrigerant and the type of the working fluid. It was shown that can deliver good performance at low generator temperatures if the refrigerant mass fraction in the strong solution is made as high as possible. Moreover, it was shown that a H2O-LiBr working pair could be useful for achieving cooling at low generator temperatures.

Factors affecting the accuracy of control of internal combustion engine with a common rail fuel system

2020 ◽  
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Design Parameters ◽  
Repeated Injection ◽  
Fuel System ◽  
Factors Affecting ◽  
Fuel Supply ◽  
Wave Phenomena ◽  
Control Accuracy

The article presents an overview of the operation of the battery fuel system with multiple injection, as well as the factors affecting the control accuracy of an internal combustion engine with a battery fuel system. The amount of preliminary fuel supply and the delay between preliminary and subsequent fuel supply by the electrohydraulic nozzle, as well as the tolerances for the design parameters of the electrohydraulic nozzle, are considered as influencing factors. Keywords wave phenomena; repeated injection; battery fuel system; electro hydraulic injector

Cost Optimum Parameters for Rock Bed Thermal Storage at 550–600 °C: A Parametric Study

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Kenneth Allen ◽  
Lukas Heller ◽  
Theodor von Backström
Keyword(s):  
Parametric Study ◽  
Particle Diameter ◽  
Thermal Storage ◽  
Design Parameters ◽  
Levelized Cost Of Electricity ◽  
United States Dollar ◽  
Capital Costs ◽  
Mass Fluxes ◽  
Rock Bed ◽  
Biot Numbers

A major advantage of concentrating solar power (CSP) plants is their ability to store thermal energy at a cost far lower than that of current battery technologies. A recent techno-economic study found that packed rock bed thermal storage systems can be constructed with capital costs of less than 10 United States dollar (USD)/kWht, significantly cheaper than the two-tank molten salt thermal storage currently used in CSP plants (about 22–30 USD/kWht). However, little work has been published on determining optimum rock bed design parameters in the context of a CSP plant. The parametric study in this paper is intended to provide an overview of the bed flow lengths, particle sizes, mass fluxes, and Biot numbers which are expected to minimize the levelized cost of electricity (LCOE) for a central receiver CSP plant with a nominal storage capacity of 12 h. The findings show that rock diameters of 20–25 mm will usually give LCOE values at or very close to the minimum LCOE for the combined rock bed and CSP plant. Biot numbers between 0.1 and 0.2 are shown to have little influence on the position of the optimum (with respect to particle diameter) for all practical purposes. Optimum bed lengths are dependent on the Biot number and range between 3 and 10 m for a particle diameter of 20 mm.

Seismic stability analyses of reinforced tapered landfill cover systems considering seepage forces

2018 ◽  
Vol 36 (4) ◽  
pp. 361-372 ◽  
Author(s):  
Afshin Khoshand ◽  
Ali Fathi ◽  
Milad Zoghi ◽  
Hamidreza Kamalan
Keyword(s):  
Parametric Study ◽  
Limit Equilibrium ◽  
Practical Method ◽  
Seismic Stability ◽  
Design Parameters ◽  
Cover System ◽  
Landfill Cover ◽  
Cover Systems ◽  
Landfill Cover System ◽  
The Stability

One of the most common and economical methods for waste disposal is landfilling. The landfill cover system is one of the main components of landfills which prevents waste exposure to the environment by creating a barrier between the waste and the surrounding environment. The stability and integrity of the landfill cover system is a fundamental part of the design, construction, and maintenance of landfills. A reinforced tapered landfill cover system can be considered as a practical method for improving its stability; however, the simultaneous effects of seismic and seepage forces in the reinforced tapered landfill cover system have not been studied. The current paper provides a solution based on the limit equilibrium method in order to evaluate the stability of a reinforced tapered landfill cover system under seismic and seepage (both horizontal and parallel seepage force patterns) loading conditions. The proposed analytical approach is applied to different design cases through parametric study and the obtained results are compared to those derived from literature. Parametric study is performed to illustrate the sensitivity of the safety factor (FS) to the different design parameters. The obtained results reveal that parameters which describe the geometry have limited effects on the stability of the landfill cover system in comparison to the rest of the studied design parameters. Moreover, the comparisons between the derived results and available methods demonstrate good agreement between obtained findings with those reported in the literature.

The Application of Fuzzy Synthesis Evaluation Method on Assessing Bridge Durability

2012 ◽  
Vol 594-597 ◽  
pp. 1033-1037
Author(s):  
Fei Zheng ◽  
Yu Wang ◽  
Pu Yang Zhang
Keyword(s):  
Evaluation Method ◽  
Concrete Bridges ◽  
Service Performance ◽  
Fuzzy Mathematics ◽  
Factors Affecting ◽  
Index Model ◽  
Design Requirements ◽  
The Difference ◽  
Fuzzy Synthesis Evaluation ◽  
Durability Of Concrete

Assessment of the structure durability of concrete bridge in service is crucial for determining whether their service performance is meeting the design requirements or not. In this paper we classify the whole structure of bridge into two levels, i.e.bridge structure and bridge components. A two-level-multi-index model for evaluating the durability of concrete bridges in service is established based on the dependent functions of various factors, in which the dependent functions are chosen in accordance with the difference of various factors affecting the deterioration of durability of components. In this model, the durability of the bridge is divided into five different fuzzy levels: intact, disrepaired, damaged, severely damaged, and dangerous. Finally, based on fuzzy mathematics theory, the durability level of a bridge in practice is evaluated by using the maximum subordination principle.

scholarly journals ARMOUR UNIT STRUCTURAL RESPONSE - A PARAMETRIC STUDY

1988 ◽  
Vol 1 (21) ◽  
pp. 176
Author(s):  
C. David Anglin ◽  
William F. Baird ◽  
Etienne P.D. Mansard ◽  
R. Douglas Scott ◽  
David J. Turcke
Keyword(s):  
Wave Height ◽  
Parametric Study ◽  
Structural Integrity ◽  
Design Procedure ◽  
Structural Response ◽  
Design Parameters ◽  
Coastal Structures ◽  
Log Normal ◽  
Wave Induced ◽  
Hydraulic Stability

There is a general lack of knowledge regarding the nature and magnitude of loads acting on armour units used for the protection of rubblemound coastal structures. Thus, a comprehensive design procedure incorporating both the hydraulic stability and the structural integrity of the armour units does not exist. This paper presents the results of a detailed parametric study of the structural response of armour units to wave-induced loading in a physical breakwater model. The effect of the following design parameters is investigated: breakwater slope, armour unit location, wave period and wave height. This research has made a number of significant contributions towards the development of a comprehensive design procedure for concrete armour units. It has identified a linear relationship between the wave-induced stress in the armour units and the incident wave height. In addition, it has shown that the conditional probability of waveinduced stress given wave height can be estimated by a log-normal distribution. Finally, a preliminary design chart has been developed which incorporates both the structural integrity and the hydraulic stability of the armour units.

Design & Analysis of Steam Drum Based on ASME Boiler and Pressure Vessel Code, Section VIII Div.2 & Div.3

2016 ◽  
Vol 852 ◽  
pp. 511-517
Author(s):  
Vishal Payghan ◽  
Dattatray N. Jadhav ◽  
Girish Y. Savant ◽  
Sagar Bharadwaj
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Pressure Vessel ◽  
Design Parameters ◽  
Plastic Collapse ◽  
Finite Element Stress Analysis ◽  
Process Plant ◽  
Section Viii ◽  
Design Requirements ◽  
Steam Drum

Process plant industries have equipment working on high pressure and high temperature environments. The ASME Boiler and Pressure Vessel Code, Section VIII provides rules for construction of the pressure vessel. The purpose of this paper is to have comparative study for design and analysis of steam drum using ASME Section VIII Div. 2 and Div. 3. Steam drum is a part of boiler system and works at high pressure and high temperature. Normally, Steam drum design is based on ASME Section VIII Div. 2, Part 4, design by rule and Part 5, design by analysis; which has been carried out in the present study. In this paper, design of the same equipment is studied using Part KD, Design requirements of ASME Section VIII Div. 3 with similar design parameters. Finite Element Stress Analysis of both design has been done as per code requirements to check the plastic collapse. In this study, it is observed that there is reduction in the required thickness for design based on Div. 3. Finally, the reduced required thickness leads to considerable weight reduction of the equipment and thus increased competitiveness.

scholarly journals Accuracy analysis and optimization of infrared guidance test device

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402092265
Author(s):  
Zhou Wang ◽  
Yin Chen ◽  
Tao Wang ◽  
Bo Zhang
Keyword(s):  
Physical Simulation ◽  
Orthogonal Experiment ◽  
Target Position ◽  
Design Parameters ◽  
Test Device ◽  
Factors Affecting ◽  
Pointing Error ◽  
Maximum Deformation ◽  
Minimum Deformation ◽  
Shell Optimization

As an important modern weapon, the development of infrared-guided missile reflects comprehensive national strength of a country. Therefore, it is especially important to establish a semi-physical simulation device to test the performance of missile, and the test device requires high accuracy. Based on the above background, an infrared guidance test device is designed in this article. The accuracy of its shell and rotating mechanism are studied in detail, and the error factors are quantified to provide theoretical basis for structural optimization. The orthogonal experiment design reduces the number of sensitivity analysis experiments on key design parameters. Factors affecting the maximum deformation and overall quality of the shell were determined. The range method was used to analyze sensitivity factors, and the final optimization result that met the minimum deformation and minimum quality was determined. Experimental results show that the rotation error of the main shaft of the rotating mechanism includes axial, radial, and angular motion errors, and experimental value is basically consistent with theoretical value. After the shell optimization, the infrared target pointing error [Formula: see text] and the infrared target position offset error ξ′ = 0.1525 mm meet the accuracy requirements. This method can provide new ideas for precision research and optimization of structural design of rotating mechanism.

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