Rational Analysis Method Research Articles

Assessing the Quality of Life of Regional Centres in Poland in the Context of Smart and Sustainable Cities

Abstract The article addresses the issue of quality of life in cities based on developed methodology. A multidimensional approach was adopted, namely 28 subindices characterizing seven dimensions affecting the quality of life in 18 provincial cities in Poland. The developed methodology consisted of two stages. In the first stage, using the indicators, the values of quality-of-life indices for the studied dimensions were determined. In the second stage, using these results, the values of the total quality-of-life indices in the studied cities were measured. Then, rankings for the cities in question were created. In addition, based on the values of the dimension indices and total indices, the levels of quality of life were determined. Relationships between parameters characterizing the sizes of studied cities and their wealth and the determined quality of life were also measured. The Gray Rational Analysis method was used for ranking, and three objective analytical methods were used to determine index weights: Equal weight, Entropy and CRITIC, and the Laplace’s criterion. The results indicate that living standards in the studied cities vary widely, both in terms of the value of the total index and the indices of individual dimensions. The best living conditions were found in Warsaw (the capital of Poland), Białystok and Olsztyn, and the worst in Kielce and Szczecin.

DEM Analysis of Track Ballast for Track Ballast–Wheel Interaction Simulation

This study aims to suggest a rational analysis method for a track ballast–wheel interaction that could be further developed to model the interaction in a train-derailment event, based on the discrete-element method (DEM). Track ballast is filled with gravel to form the trackbed. Although finite-element analysis (FEA) is widely applied in structural analysis, track ballast cannot be analyzed using conventional FEA because this approach does not allow separation of elements that share nodes. The DEM has been developed to analyze the dynamic behavior of separable objects, assuming that the objects are rigid. Therefore, track ballast can be modeled as separable rigid pieces of gravel, and its dynamic behavior can be analyzed using a rational contact model. In this study, a rational numerical strategy for track ballast–wheel interaction was investigated using the DEM approach. The suggested analysis method was validated through comparison with the experimental results of a drop test. In addition, case studies were conducted to investigate the effects of the contact-model parameters on the simulation result.

Misleading Epidemiological and Statistical Evidence in the Presence of Simpson's Paradox: An Illustrative Study Using Simulated Scenarios of Observational Study Designs.

This study empirically illustrates the mechanism by which epidemiological effect measures and statistical evidence can be misleading in the presence of Simpson's paradox and identify possible alternative methods of analysis to manage the paradox.Three scenarios of observational study designs, including cross-sectional, cohort, and case-control approaches, are simulated. In each scenario, data are generated, and various methods of epidemiological and statistical analyses are undertaken to obtain empirical results that illustrate Simpson's paradox and mislead conclusions. Rational methods of analysis are also performed to illustrate how to avoid pitfalls and obtain valid results.In the presence of Simpson's paradox, results from analyses in overall data contradict the findings from all subgroups of the same data. This paradox occurs when distributions of confounding characteristics are unequal in the groups being compared. Data analysis methods which do not take confounding factor into account, including epidemiological 2×2 table analysis, independent samples t-test, Wilcoxon rank-sum test, chi-square test, and univariable regression analysis, cannot manage the problem of Simpson's paradox and mislead research conclusions. Mantel-Haenszel procedure and multivariable regression methods are examples of rational analysis methods leading to valid results.Therefore, Simpson's paradox arises as a consequence of extreme unequal distributions of a specific inherent characteristic in groups being compared. Analytical methods which take control of confounding effect must be applied to manage the paradox and obtain valid research evidence regarding the causal association.

Distribution of Landscape Architecture Based on 3D Images and Virtual Reality Rationality Study

In order to ensure the rationality of landscape design, it is of great practical significance to simulate the planning effect. Aiming at the problems of traditional garden landscape distribution simulation technology, this paper designs a new garden landscape distribution rationality simulation technology based on three-dimensional image and virtual reality technology. Firstly, a rational analysis method for landscape garden distribution based on three-dimensional images is proposed. Based on the correlation between different coordinate systems under a specific angle of view, a camera pose matrix is constructed, and SURF feature point detection is performed on the landscape garden image and the above feature points are clustered and matched. Secondly, the three-dimensional image reconstruction of the landscape garden image is realized based on the registered image feature points. Based on the three-dimensional image reconstruction results and virtual reality technology, the three-dimensional image analysis of the rationality of landscape distribution is completed. Finally, the case analysis and performance test results illustrate the superiority of the realized landscape garden distribution rationality technology. This method can provide scientific reference and basis for the modern landscape gardening industry to adopt three-dimensional images and other technologies.

Ultimate behavior of steel cable-stayed bridges - I. Rational ultimate analysis method -

This paper presents an investigation on the ultimate behavior of steel cable-stayed bridges. In general, various nonlinear factors affect the global behavior of cable-stayed bridges, such as material nonlinearities, cable-sag effect, beam-column effect, large displacement effect, and girder-mast-cable interaction. These effects also affect the ultimate behavior of cable-stayed bridges. Therefore, a rational analysis method should be performed to study the ultimate behavior of cable-stayed bridges. Because of various nonlinearities, the analysis should be based on the theory of nonlinear finite element analysis. Moreover, rational ultimate analysis can reflect characteristics of the design and construction of cable-stayed bridges. In this study, a rational ultimate analysis method for steel cable-stayed bridges is developed and proposed based on the theory of nonlinear finite element analysis. A two-step analysis method is proposed and used in this study. Through this analysis scheme, the structural state under dead load is considered before the live load analysis. The developed program is used to study the ultimate behavior of steel cable-stayed bridges under vertically applied live load cases. Analytical study is used to investigate governing ultimate modes under the considered live load cases. By comparing the analysis results under each live load case, the critical load case is determined. The effects of geometric nonlinearities and material nonlinearities on the ultimate behavior of steel cable-stayed bridges are studied by performing geometric nonlinear analysis, as well as ultimate analysis.

Evaluation of internal and external stresses on the SPT sampler

The N<sub>SPT</sub> index is usually used in empirical correlations to estimate parameters of the soil, carrying capacity, foundation settlement, etc. Because these correlations have no scientific basis, researchers have been developing rational methods of analysis, based on energy concepts. The amounts of energy involved in the SPT test are evaluated by the EFV method. With force and acceleration records, amounts of energy, equipment efficiency, experimental dynamic reaction force of the soil and stresses acting on the sampler were assessed. In this study, a sample extractor system was designed, which consists of a base, a hydraulic cylinder and a load cell. The objective of this equipment is to experimentally quantify the internal friction force, allowing the stresses acting on the sampler to be evaluated. Also, the Aoki's a parameter, which is the ratio of internal friction and external friction between the ground and the sampler, could be calculated.

A stochastic model for examining along-wind loading uncertainty and intervention costs due to wind-induced damage on tall buildings

This study describes some recent results of a numerical study on the wind-induced response of a tall building, contaminated by along-wind loading uncertainty. The study also proposes the use of “intervention costs” in the form of a dimensionless random variable, which nonlinearly depends on the dynamic response of the structure, for the examination of the structural performance during high-wind events.The CAARC building is employed as the benchmark structure. Three nonlinear reduced-order models are used to describe the dynamic response. In these models various hypotheses are introduced to systematically and efficiently simulate both loading uncertainty and cost variability. The generalized models are formulated in terms of stochastic differential equations and are approximately solved by equivalent stochastic linearization. In the case of loading uncertainty analysis, the joint probability density function of the roof-top lateral dynamic displacements in the two primary bending planes of the building is determined as a function of the mean wind speed and the standard deviation of a parametric error term. Dependence of the cross-correlation among the two response components on the input standard deviation of the parametric error term is observed. In the case of the intervention cost analysis, it is noted that the main contributing factor to the distribution of the intervention cost random variable is the mean wind speed.The combination of wind loading uncertainty and projected intervention costs on the dynamic response of the structure is the first step towards the implementation of alternative but rational analysis methods for performance-based wind engineering, applied to tall buildings.

The Interpretation of the Rules of Formal Beauty in Landscape Design

The artistry of landscape design is rested with the components and principles, with the practice of rational methods of analysis, and then, to lay the foundation on the relationships of design, art, economy, comprehensive function. With the aesthetic and scientific view to have repeated comparisons can eventually come up with a good design. Following the regular laws of formal beauty has become one of the guiding principles of landscape design. A study of the laws of formal beauty plays an essential role in landscape design to create an optimal human landscape system.

ASSESSMENT OF THE FINANCIAL POSITION OF A COMPANY: THEORETICAL ASPECT

Abstract. The article provides evidence on company’s financial position and its perspectives depending on rational methods of analysis providing reliable and exact evaluations. It is stated that if the absolute and relative financial indicators are not provided, indicator standardization and the analysis of standardized values are not defined, and the complex indicator which shows the synthetic financial position of a company is not presented; without the analysis and assessment of structural changes of the indicator it would be difficult to ensure a company’s successful position in the competitive environment. The article presents methods of analysis of the compound indicator structural changes.Key words: financial position, methods of analysis, analysis of compound indicator structure

Research on Pile Foundation of Transmission Tower Stability Analysis Based on Numerical Simulation in Karst Areas

The stability of the karst area transmission towers pile foundation and engineering deal with the problem, the success or failure related to the electric power system operation, the karst area transmission towers pile foundation stability of the subject, the power sector is currently no in-depth case studies, qualitative analysis has been used method and semi-quantitative analysis of the reliability of the method of evaluation results is restricted, and thus how to seek a more rational analysis method and its application in theory worthy of further exploration. In this paper, numerical simulation conducted in-depth study and exploration of a karst area transmission tower pile stability evaluation, design, construction and operation of the project has a certain reference value, has certain reference significance for similar construction projects.

Simplified Method for Failure Analysis of Concrete Beams Prestressed with External Tendons

The flexural strength of externally prestressed beams depends on the tendon stress at failure. If the tendon is free to slip at the deviators its stress will depend on the global deformation of the whole structure. Thus the tendon stress at failure, and consequently, the flexural strength cannot be evaluated by a local analysis of the critical sections, but a nonlinear analysis of the whole beam-tendon structural system is required. In the past, simplified formulas were proposed to calculate the tendon stress increment at failure avoiding the need for a nonlinear analysis of the entire structure. Some of these formulas have been adopted as code recommendations. Some approaches however do not seem to be consistent with the actual behavior of externally prestressed beams and in some cases excessively high increments of stress are recommended. On the other hand, other approaches appear to be too conservative. In this work a new simplified and rational method of analysis based on shape functions approximating deformations is proposed to study the tendon stress increment and consequently the flexural strength of externally prestressed concrete beams. The proposed simplified method reduces the analysis of externally prestressed structures from a global structure problem to an easier section problem.

Simplified Method for Analysis of Piles Undergoing Lateral Spreading in Liquefied Soils

The analysis of piles subjected to lateral spreading is burdened by the uncertainties associated with the spreading of liquefied soils. Namely, it is very difficult to reliably predict the magnitude and spatial distribution of post-liquefaction ground displacements and also there are uncertainties regarding the stiffness and strength of liquefied soils undergoing lateral spreading. In view of the unknowns involved, there is a need for a sufficiently accurate, yet simple and rational method of analysis that will permit to efficiently evaluate the pile response for various magnitudes of ground displacements and stiffness properties of the spreading soils. In this paper a simple analytical solution is presented for evaluating the pile response to lateral spreading with due consideration of the kinematic mechanism associated with spreading of liquefied soils and the need to estimate the inelastic response and damage to piles. Particular attention is given to the loads arising from a non-liquefied crust layer at the ground surface and to the kinematic effects at the interface between the liquefied layer and underlying non-liquefied layer. A closed-form solution for linear behavior is first derived based on the classical equation for beam on elastic foundation. The method is then extended over the range of nonlinear behavior using the equivalent linear approach for simplified modeling of the deformational behavior of the pile and soil. Key parameters influencing the pile response and being associated with intrinsic uncertainties are identified and discussed. The proposed method permits to estimate the inelastic response of piles, yet it is a simple analytical solution that requires a few conventional engineering parameters as input. The method is envisioned as a rational tool that will be of practical use in the preliminary assessment of piles and uncertainties involved.

A Simplified Numerical Model for an Integral Abutment Bridge Considering the Restraining Effects Due to Backfill

This paper presents the simplified but more rational analysis method for the prediction of additional internal forces induced in integral abutment bridges. These internal forces depend upon the degree of restraint provided tc the deck by the backfill soil adjacent to the abutments and piles. In addition, effect of the relative flexural stiffness ratio among pile foundations, abutment, and superstructure on the structural behavior is also an important factor. The first part of the paper develops the stiffness matrices, written in terms of the soil stiffness, for the lateral and rotational restraints provided by the backfill soil adjacent to the abutment. The finite difference analysis is conducted and it is confirmed that the results are agreed well with the predictions obtained by the proposed method. The simplified spring model is used in the parametric study on the behavior of simple span and multi-span continuous integral abutment PSC beam bridges in which the abutment height and the flexural rigidity of piles are varied. These results are compared with those obtained by loading Rankine passive earth pressure according to the conventional method. From the results of parametric study, it was shown that the abutment height, the relative flexural rigidity of superstructure and piles, and the earth pressure induced by temperature change greatly affect the overall structural response of the bridge system. It may be possible to obtain more rational and economical designs for integral abutment bridges by the proposed method.

Structural response function approach for evaluation of thermal striping phenomena

A rational analysis method for thermal stress induced by fluid temperature fluctuation is developed, by utilizing frequency response characteristics of structures. High frequency components of temperature fluctuation are attenuated during a transfer process from fluid to structures. Low frequency components hardly induce thermal stress, since temperature homogenization in structures. Based on investigations of the frequency response mechanism, a frequency response function of structures was derived, which can predict stress amplitudes on structural surfaces from fluid temperature amplitudes and frequencies. It is formulated by multiplication of the effective heat transfer and the effective thermal stress functions. The frequency response function was applied to fatigue analysis of nuclear components, and clarified relation of fatigue damage to thermal hydraulic and structural design parameters.

A generalized design-based elastoplastic analysis of steel frames by section assemblage concept

In the advanced elastoplastic analysis of steel frames, the linear interaction function for axial force and moment is commonly used for the lump plasticity model in assessing the capacity of a section. This linear interactive method is conservative and classified as the simplified approach in some national design codes such as BS5950. This paper proposes a more rigorous and rational method of analysis by considering the section capacity under moment and axial force via the modelling of an I or a H section by three rectangular strips. It produces a more consistent, accurate and rational assessment of section strength. It is convenient to use as it does not require the modification of the linear interaction curve under high or low axial load, in contrast to the load and resistance factor design specification. The analysis output by the proposed method meets the design code requirement for practical design under the catalogue of rigorous approaches in BS5950. Also, this method considers various effects such as deteriorating stiffness, initial imperfection, residual stress and geometrical and material nonlinearities simultaneously. The distinct advantage for the proposed method is that it does not use the conservative linear axial force — moment interactive formula or its empirically modified form for inelastic analysis. Instead, it employs a refined technique for the formulation of the full yield surface based solely on the section properties, which is general, rational and produces a more economical design.

A re-examination of the analysis of in-plane matrix failures in fibrous composite laminates

Rational analysis methods are presented to cover, separately, possible brittle fracture and ductile yield failures of the matrix in fibre/polymer composite materials subjected to purely in-plane loads. The models cover both carbon fibres, which customarily fail before the matrix, and glass-fibre composites in which the matrix usually fails first. Delaminations, both at edges and from damage, are excluded, because they need quite different analyses. Customary progressive-failure and ply-discounting analyses are shown to be erroneous, because one cannot characterize a fracture-mechanics problem with strength-of-material analyses. An explanation is provided for why, unlike fibre failures and matrix yielding, matrix cracking cannot be assessed on a ply-by-ply basis. There is an interaction with adjacent plies which can act as crack stoppers. In other words, not even the classical laminate theory is valid when the matrix really cracks. Gaps in the understanding of the subject, in regard to residual thermal stresses, are identified. A distinction is drawn between conventional carbon-fibre/polymer composites, for which even a crude analysis of matrix failures can suffice because only structurally insignificant matrix microcracking precedes the fibre failures in properly designed laminates and in glass-fibre-reinforced plastics in which the matrix really can fail first. In metal-matrix composites, a far more accurate model will be needed because the matrix then carries most of the load. The knowledge of this subject 30 years ago is shown to be far superior to what is commonly used to analyse composite materials today and it is suggested that the introduction of the many abstract mathematical interactive failure criteria, valid only for truly homogeneous anisotropic materials, was largely responsible for this.

Analysis of bath composition with indirect indexes using experimental design methods

A rational method of analysis of the components of spinning and plasticization baths based on indirect indexes is proposed. A program was written for an IBM PS/AT PC to automate the calculation procedure. Convenient diagrams which can be used when no PC is available were developed for estimating the concentrations of the components.

The nature of the two opening levels following an overload in fatigue crack growth

During the period of retarded fatigue crack growth following a single tensile overload, two crack opening levels are observed. Different interpretations have been put forth concerning the nature of these opening events. In one proposal, the two opening events are considered to occur in plane strain, first behind the crack tip and then at the crack tip. In another proposal, the first opening event occurs in the plane strain portion of the crack front and the second in the plane stress portion of the crack front. In this paper, critical experiments designed to clarify this issue are described. In most of the experiments, the aluminum alloy 6061-T6 was used. Additional tests were made using the aluminum alloy 7090-T6 and the titanium alloy IMI 829. The results of these experiments show that over the entire range of ΔK, including the near-threshold range, the two opening events are associated with a plane strain followed by a plane stress opening process. The results are important in that they not only shed light on the mechanism of crack retardation following an overload, but they also provide a basis for the development of a rational method of analysis for the calculation of the number of delay cycles following an overload which includes the effects of thickness and ΔK level. Based upon the findings of this study, a semiempirical method for the determination of the number of delay cycles following an overload is presented. The number of delay cycles predicted by this method is found to be in good agreement with the results of the present investigation as well as with other results from the literature.

Predicting Deflections of Reinforced Concrete Beams Analytically

A rational method of analysis is proposed for the calculation of creep deflections of reinforced concrete beams under sustained service loads. The method introduces the use of a fictitious modulus relating, for a given section under bending, the initial stress in concrete with the final strain after a period of sustained load. The requirements of strain compatibility and equilibrium of a section are used, in conjunction, to determine the position of neutral axis and strain and stress distributions after creep. The long‐term flexural rigidity of the member, (EI), is determined from a knowledge of a new neutral axis and a new modular ratio and is used to calculate the final deflections. The approach for calculating long‐term deflections is similar to the current American Concrete Institute (ACI) procedure for calculating short‐term deflections. The accuracy of the analysis is verified by comparison with several experimental measurements of beam deflections. The result is good correlation between the theoretical values and measured values.

A Design Procedure for Evaluating the Tube Axial Load due to Thermal Effects in Multi-Pass Fixed Tubesheet Exchangers

The unequal length change of the tubes in various tube passes of a multi-tube pass fixed or floating head tubular exchanger produces axial tube loads which may be substantial in some operating units. This paper provides a rational analysis method, heretofore unavailable to the design community, to quantify the effect of multi-pass thermal expansion on the tube axial load. A numerical example is used to illustrate the solution procedure.