New Concepts on Two-Dimensional Data Visualization With Applications in Engineering Analysis and Design

2012 ◽  
Vol 12 (2) ◽  
Author(s):  
P. A. Simionescu ◽  
Mehrube Mehrubeoglu
Keyword(s):  
Graphical Representation ◽  
Damping Ratio ◽  
Two Dimensional ◽  
Engineering Analysis ◽  
Science And Engineering ◽  
Single Degree Of Freedom ◽  
Analysis And Design ◽  
New Concepts ◽  
New Ideas ◽  
Detailed Application

The use of information visualization in engineering analysis and design has increased exponentially, making it indispensable in science and engineering education. In this paper, several new concepts on graphical representation of two-dimensional data are presented, and their implementation in a computer program called D_2D detailed. Application examples include mechanism kinematics, vibrations, and optimizations. New ideas on plotting inequalities of two variables, damping ratio evaluation of single degree-of-freedom vibratory systems, and time ratio calculation of crank-driven mechanisms are presented in paper.

Notes about Terminology and Nomenclature

1965 ◽  
Vol 69 (659) ◽  
pp. 768-768
Author(s):  
N. Kurti
Keyword(s):  
Excited States ◽  
Hydrogen Isotope ◽  
Radioactive Isotopes ◽  
Science And Engineering ◽  
New Concepts ◽  
Rate Of Increase ◽  
New Ideas ◽  
The Many ◽  
Theoretical Assessment ◽  
Technical Terms

There seems to be a disturbing rate of increase in new scientific and technical terms. The purpose of these notes is to stimulate a discussion of this trend.When inventing or introducing new terms the following points should be borne in mind: (1) is a new word necessary or desirable, (2) is it apt and well-constructed?As regards (1) the usual justification is that science and engineering are developing so fast that in order to communicate new ideas and new concepts an increase in the vocabulary is essential. This, however, can be overdone. The very act of coining a new word implies a theoretical assessment, almost an acknowledgment of the fact that a concept or phenomenon, or particle has a well defined identity. The following, somewhat exaggerated examples, illustrate this point. It would have been most unfortunate if spectroscopists at the end of the last century had insisted on giving one and the same chemical element different names according to the wavelength of the light they emitted. I wonder whether the many names allocated to elementary particles today may not become an embarrassment should it turn out that they are in many cases just excited states of one and the same particle. Conversely, one must applaud the restraint of the nuclear physicists for not giving separate names to various radioactive isotopes. After all, as far as nuclear properties go, many isotopes (e.g.57Co, 58Co, 60Co) have very little in common. And, although we have a separate name for the heavy hydrogen isotope (deuterium), physicists and chemistsi have so far resisted the temptation to give the light isotope of helium (3He) a name and we are still spared “trelium”.

scholarly journals Estimation of Additional Equivalent Damping Ratio of the Damped Structure Based on Energy Dissipation

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Xiuyan Hu ◽  
Qingjun Chen ◽  
Dagen Weng ◽  
Ruifu Zhang ◽  
Xiaosong Ren
Keyword(s):  
Energy Dissipation ◽  
Damping Ratio ◽  
Theoretical Concept ◽  
Estimation Methods ◽  
External Excitation ◽  
Single Degree Of Freedom ◽  
Equivalent Damping ◽  
Seismic Motion ◽  
Practical Engineering ◽  
Energy Dissipation Capacity

In the design of damped structures, the additional equivalent damping ratio (EDR) is an important factor in the evaluation of the energy dissipation effect. However, previous additional EDR estimation methods are complicated and not easy to be applied in practical engineering. Therefore, in this study, a method based on energy dissipation is developed to simplify the estimation of the additional EDR. First, an energy governing equation is established to calculate the structural energy dissipation. By means of dynamic analysis, the ratio of the energy consumed by dampers to that consumed by structural inherent damping is obtained under external excitation. Because the energy dissipation capacity of the installed dampers is reflected by the additional EDR, the abovementioned ratio can be used to estimate the additional EDR of the damped structure. Energy dissipation varies with time, which indicates that the ratio is related to the duration of ground motion. Hence, the energy dissipation during the most intensive period in the entire seismic motion duration is used to calculate the additional EDR. Accordingly, the procedure of the proposed method is presented. The feasibility of this method is verified by using a single-degree-of-freedom system. Then, a benchmark structure with dampers is adopted to illustrate the usefulness of this method in practical engineering applications. In conclusion, the proposed method is not only explicit in the theoretical concept and convenient in application but also reflects the time-varying characteristic of additional EDR, which possesses the value in practical engineering.

scholarly journals Parametric optimization of the cross-section and shape of the longitudinal member in frontal impact

2019 ◽  
Vol 140 ◽  
pp. 02013
Author(s):  
Dmitry Bogdanov ◽  
Yury Boldyrev ◽  
Pavel Cvetkov ◽  
Oleg Klyavin ◽  
Ilya Davydov ◽  
...  
Keyword(s):  
Cross Section ◽  
Parametric Optimization ◽  
Numerical Procedure ◽  
Software Systems ◽  
Engineering Analysis ◽  
Frontal Impact ◽  
Mathematical Statement ◽  
Analysis And Design ◽  
Optimization Task ◽  
Python Programming

The article considers the problem of optimal design of car body elements (longitudinal members) according to the chosen criteria. Both the questions of formulation of the optimization task and individual problems of its solution are studied. The mathematical statement of the problem is considered. Thus, the most attention is given to consideration of realisation of used numerical procedure of optimization. The system of numerical calculations is based on the most widely spread software systems for engineering analysis and design. The developed scripts on Python programming language are briefly considered. Results of optimization of longitudinal members of the car are given.

scholarly journals IMAGES CONVERTER OF GEOLOGIC- LITHOLOGICAL PROFILES

2021 ◽  
Vol 445 (1) ◽  
pp. 121-126
Author(s):  
D. B. Nurseitov ◽  
N. A. Toiganbayeva ◽  
M. O. Kenzhebayeva
Keyword(s):  
Image Segmentation ◽  
Distribution Density ◽  
Graphical Representation ◽  
Oil Field ◽  
Object Oriented Programming ◽  
Two Dimensional ◽  
Dimensional Array ◽  
Digital Format ◽  
The Matrix ◽  
Oriented Programming Language

The article is devoted to the program "Converter", which allows you to translate the geologic-lithological profile of a mineral field into a digital format in the form of a two-dimensional array. The object-oriented programming language Python was used to write the program. The NumPy, OpenCV, and MatPlotlib libraries are actively used. The implementation of this program is based on image segmentation and finding the prevailing colors in the OpenCV library. Image segmentation is a preliminary step in image processing. The obtained values allow you to find out the density distribution in the area under consideration. The program "Converter" has a good graphical representation of the results obtained using the MatPlotlib library. The program writes the final converted result as a two-dimensional array to a text file along the desired path. Thus, the matrix is easy to read for further use in conjunction with other programs. The purpose of this work was to create a program that converts the geologic-lithological profile of the field into a digital format in the form of a two-dimensional array, for further use of this matrix as the distribution density of the oil field. The "Converter" program converts any geologic-lithological profile into a two-dimensional array in a matter of minutes.

scholarly journals A Normalized Hysteretic Energy Spectrum for Energy-Based Seismic Design

2020 ◽  
Vol 198 ◽  
pp. 04004
Author(s):  
Cuiling Ma ◽  
Changbing Chen ◽  
Xiaotang Lv ◽  
Jian Bian ◽  
Yuan Feng ◽  
...  
Keyword(s):  
Seismic Design ◽  
Soil Type ◽  
Damping Ratio ◽  
Site Classification ◽  
Single Degree Of Freedom ◽  
Hysteretic Energy ◽  
Type Site ◽  
Set Up ◽  
Ground Motion Records ◽  
Ductility Ratio

To disclose the impacts of hysteretic energy (HE) demand on energy-based seismic design, this paper introduces the dimensionless parameter βEH to express the cumulative HE indirectly and establishes the βEH spectrum for energy-based seismic design. After analyzing numerous seismic responses of a single degree-of-freedom (SDOF) system, the author set up a simplified βEH spectral formula based on the genetic algorithm. Then, 750 ground motion records were selected according to Chinese site classification, and used to examine the effects of soil type and damping ratio on the βEH spectra. The results show that the soil type, site group and damping ratio have significant effects on the βEH spectra; the ductility ratio has an impact on the spectral value but not the spectral shape.

Guidelines for Optimizing the Error in Area Ratio Damping Estimation Method

2021 ◽  
Author(s):  
Balija Santoshkumar ◽  
Firas A. Khasawneh
Keyword(s):  
Damping Ratio ◽  
Estimation Method ◽  
Optimal Number ◽  
Free Response ◽  
Single Degree Of Freedom ◽  
Recent Approach ◽  
Number Of Cycles ◽  
Damped Systems ◽  
Two Peaks ◽  
Damping Estimation

Abstract The logarithmic decrement (log-dec) is one of the most popular methods for viscous damping estimation in linear, single degree of freedom systems. It estimates the damping ratio by examining the decay in the amplitude between two peaks some number of cycles apart. The accuracy in the estimation is sensitive to the chosen number of cycles, where the latter can be optimized such that the uncertainty in the estimation is minimized. However, the log-dec method is not suitable for systems with high damping ratios (approximately > 0.3). Another recent approach for damping estimation is based on considering a ratio of the amplitudes of the positive and negative areas in the free response of the oscillator. Although prior works on the areas method only tested lightly damped systems, we show here that — in contrast to log-dec — this approach can estimate the damping ratio over the whole range of underdamped linear oscillators. However, in contrast to log-dec, there are no available guidelines on how many areas to include in the damping estimation. In this work, we derive uncertainty analysis expressions for the areas method and we utilize them to obtain the optimal number of areas to use. Our results show that for a very low damping ratio (< 0.01), choosing more than two areas in the estimation increases the uncertainty. In contrast, for moderate to high damping (between 0.05 and 1), we need to consider all the available areas in the estimation. One caveat in the range of high damping (between 0.3 and 1) is that while it is desirable to include all the available areas, uncertainty increases when considering up to 3 areas. Therefore, if only 4 areas are available in this range, then to reduce the uncertainty in the estimate only the first two areas must be considered. The results are verified using a large number of numerical simulations including different levels of noise.

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