Generic transformation models for some intact rock properties

2018 ◽  
Vol 55 (12) ◽  
pp. 1702-1741 ◽  
Author(s):  
Jianye Ching ◽  
Kuang-Hao Li ◽  
Kok-Kwang Phoon ◽  
Meng-Chia Weng

A global intact rock database of nine parameters, including uniaxial compressive strength and Young’s modulus, is compiled from 184 studies. This database, labeled as “ROCK/9/4069”, consists of 27.5% igneous rock, 59.4% sedimentary rock, and 13.1% metamorphic rock. The vast majority (>95%) of intact rocks in the database are in their natural moisture contents. About 14% of the data points are for weathered rocks and about 4% are foliated metamorphic rock. It is found that most existing transformation models are data-specific or site-specific in the sense that they fit well to their own calibration databases, but do not necessarily fit well to ROCK/9/4069. One can infer that transformation models for intact rocks are more data–site dependent than those for soils. It is evident that ROCK/9/4069 has coverage wider than most existing transformation models. The ROCK/9/4069 database is then adopted to calibrate the bias and variability of existing transformation models. Transformation models with relatively large application ranges and relatively small transformation uncertainties are selected as generic transformation models. These generic models can be valuable for scenarios where site-specific models are not available, e.g., construction projects with insufficient budget or the preliminary design stage of a project.

Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.


Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 395-405
Author(s):  
Arsalan Alavi ◽  
Elena Mele ◽  
Reza Rahgozar ◽  
Ehsan Noroozinejad Farsangi ◽  
Izuru Takewaki ◽  
...  

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 214
Author(s):  
Ann T. W. Yu ◽  
Irene Wong ◽  
Zezhou Wu ◽  
Chi-Sun Poon

Hong Kong is a densely populated city with high-rise developments, and as in other metropolitan cities, the amount of waste generated from construction projects in the city is increasing annually. The capacity of existing landfills is expected to be saturated by the 2020s. Construction waste management has been implemented for years but the performance is still not satisfactory. The aim of this research paper is to explore and formulate strategies and measures for effective construction waste management and reduction in highly urbanized cities such as Hong Kong. A desktop study on construction waste management practices was carried out for a preliminary understanding of the current situation in Hong Kong. Semistructured interviews and focus group meetings were further conducted to shed light on how to improve construction waste reduction and management in Hong Kong. The main contributions of this research study are the potential short-term, medium-term, and long-term strategies, which are related to the design stage, tender stage, construction stage, and government support. The five major strategies recommended are financial benefits to stakeholders, public policies in facilitating waste sorting, government supports for the green building industry, development of a mature recycling market, and education and research in construction waste minimization and management.


Author(s):  
Shiyong Yang ◽  
Kikuo Nezu

Abstract An inverse finite element (FE) algorithm is proposed for sheet forming process simulation. With the inverse finite element analysis (FEA) program developed, a new method for concurrent engineering (CE) design for sheet metal forming product and process is proposed. After the product geometry is defined by using parametric patches, the input models for process simulation can be created without the necessity to define the initial blank and the geometry of tools, thus simplifying the design process and facilitating the designer to look into the formability and quality of the product being designed at preliminary design stage. With resort to a commercially available software, P3/PATRAN, arbitrarily three-dimensional product can be designed for manufacturability for sheet forming process by following the procedures given.


1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.


2021 ◽  
Author(s):  
Sacheen Bekah

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.


2021 ◽  
Author(s):  
Sacheen Bekah

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.


2021 ◽  
pp. 74-82
Author(s):  
Valery Pechenyuk ◽  
◽  
Yuri Popov ◽  

The analysis of existing aircraft structures made of metal-polymer composite materials is carried out, and a list of them with passport characteristics is compiled. The Fokker F-27 Friendship, Boeing-777 and Airbus A380, which use ARALL and GLARE materials, were selected as the aircraft under study. Formulas are determined and the distribution of normal force flows between metal and composite elements in the composition of MPCM based on aluminum sheets (aluminum-fiberglass – SIAL- 1-1, SIAL-3-1 and SIAL-1441 (9/8)) and titanium alloys (samples of titanium-carbon fiber from the patent-Example 1 and Example 3). To determine these parameters, the formulas used for a composite structure made of different materials are used. On the basis of the specification known MPCM the modified formula mixture rule for calculating the strength of new materials with a given set of orientation angles of PCM and the presence of layers of sheet metal, a comparison with standard mechanical characteristics and to show the efficiency of these formulas. Using these formulas, you can determine the strength characteristics for an arbitrary composition of the MPCM package. The features of the choice of design permissible stresses for the design of the airframe of a mainline aircraft made of metal-polymer composite material are highlighted. The concept of designing aircraft airframe elements using MPCM is considered. The results of this work will allow us to determine the rational components of the metal-polymer composite material and the structure of their distribution in the airframe design at the preliminary design stage.


2015 ◽  
Vol 22 (1) ◽  
pp. 28-35
Author(s):  
Katarzyna Żelazny

Abstract During ship design, its service speed is one of the crucial parameters which decide on future economic effects. As sufficiently exact calculation methods applicable to preliminary design stage are lacking the so called contract speed which a ship reaches in calm water is usually applied. In the paper [11] a parametric method for calculation of total ship resistance in actual weather conditions (wind, waves, sea current), was presented. This paper presents a parametric model of ship propulsion system (screw propeller - propulsion engine) as well as a calculation method, based on both models, of mean statistical value of ship service speed in seasonal weather conditions occurring on shipping lines. The method makes use of only basic design parameters and may be applied in preliminary design stage.


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