Dynamic Modeling and Experimental Testing of a Piano Action Mechanism With a Flexible Hammer Shank

2007 ◽  
Author(s):  
Adel Izadbakhsh ◽  
John McPhee ◽  
Stephen Birkett
Keyword(s):  
Experimental Testing ◽  
Rigid Bodies ◽  
Beam Model ◽  
Action Mechanism ◽  
Rayleigh Beam ◽  
Hammer Head ◽  
Main Components ◽  
The Impact ◽  
Grand Piano ◽  
Theoretical Results

The piano action is the mechanism that transforms the finger force applied to a key into a motion of a hammer that strikes a piano string. This paper presents a state-of-the-art model of a grand piano action, which is based on the five main components of the action mechanism (key, whippen, jack, repetition lever, and hammer). Even though Askenfelt and Jansson [1] detected some flexibility for the hammer shank in their experiments, all previous piano models have assumed the hammers to be rigid bodies. In this paper, we have accounted for the hammer shank flexibility using a Rayleigh beam model. It turns out that the flexibility of the hammer shank does not significantly affect the rotation of the other parts of the piano mechanism, compared with the case that the hammer shank has been modeled as a rigid part. However, the flexibility of the hammer shank changes the impact velocity of the hammer head, and also causes a greater scuffing motion for the hammer head during the contact with the string. To validate the theoretical results, experimental measurements were taken by two strain gauges mounted on the hammer shank, and by optical encoders at three of the joints.

Dynamic Modeling and Experimental Testing of a Piano Action Mechanism With a Flexible Hammer Shank

2008 ◽  
Vol 3 (3) ◽  
Author(s):  
Adel Izadbakhsh ◽  
John McPhee ◽  
Stephen Birkett
Keyword(s):  
Experimental Testing ◽  
Rigid Bodies ◽  
Beam Model ◽  
Action Mechanism ◽  
Rayleigh Beam ◽  
Hammer Head ◽  
Main Components ◽  
The Impact ◽  
Grand Piano ◽  
Theoretical Results

The piano action is the mechanism that transforms the finger force applied to a key into a motion of a hammer that strikes a piano string. This paper presents a state-of-the-art model of a grand piano action, which is based on the five main components of the action mechanism (key, whippen, jack, repetition lever, and hammer). Even though some piano action researchers (e.g., Askenfelt and Jansson) detected some flexibility for the hammer shank in their experiments, all previous piano models have assumed the hammers to be rigid bodies. In this paper, we have accounted for the hammer shank flexibility using a Rayleigh beam model. It turns out that the flexibility of the hammer shank does not significantly affect the rotation of the other parts of the piano mechanism and the impact velocity of the hammer head, compared to the case that the hammer shank has been modeled as a rigid part. However, the flexibility of the hammer shank causes a greater scuffing motion for the hammer head during the contact with the string. To validate the theoretical results, experimental measurements were taken by two strain gauges mounted on the hammer shank, and by optical encoders at three of the joints.

Dynamic Modeling and Experimental Testing of a Piano Action Mechanism

2005 ◽  
Vol 1 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Martin Hirschkorn ◽  
John McPhee ◽  
Stephen Birkett
Keyword(s):  
Rigid Body ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Experimental Testing ◽  
Individual Action ◽  
Action Mechanism ◽  
Friction Forces ◽  
Multibody Dynamic ◽  
Main Action ◽  
Grand Piano

A model for a grand piano action is proposed in this paper. The multibody dynamic model treats each of the five main action components (key, whippen, jack, repetition lever, and hammer) as a rigid body, and incorporates a contact model to determine the normal and friction forces at 13 locations between each of the contacting bodies. All parameters in the model are directly measured from experiments on individual action components, allowing the model to be used as a prototyping tool for actions that have not yet been designed or built. The behavior of the model was compared to the behavior of an experimental grand piano action and found to be very accurate for high force blows, and reasonably accurate for low force blows.

Dynamic Modelling and Experimental Testing of a Piano Action Mechanism

2005 ◽  
Author(s):  
Martin C. Hirschkorn ◽  
John McPhee ◽  
Stephen Birkett
Keyword(s):  
Rigid Body ◽  
Dynamic Model ◽  
Experimental Testing ◽  
Dynamic Modelling ◽  
Individual Action ◽  
Action Mechanism ◽  
Friction Forces ◽  
Multibody Dynamic ◽  
Main Action ◽  
Grand Piano

A new model for a grand piano action is proposed in this paper. The multibody dynamic model treats each of the five main action components (key, whippen, jack, repetition lever, and hammer) as a rigid body, and incorporates a contact model to determine the normal and friction forces at 13 locations between each of the contacting bodies. All parameters in the model are directly measured from experiments on individual action components, allowing the model to be used as a prototyping tool for actions that have not yet been designed or built. The behaviour of the model was compared to the behaviour of an experimental grand piano action and found to be very accurate for high force blows, and reasonably accurate for low force blows.

MODERN PROBLEMS OF ACCOUNTING AND ANALYTICAL ENSURING FINANCIAL RESULTS MANAGEMENT

2020 ◽  
Author(s):  
Yuliia Peniak ◽  
◽  
Nataliia Horokhovatska ◽  
Keyword(s):  
Performance Management ◽  
Enterprise Management ◽  
Goods And Services ◽  
Financial Condition ◽  
General Evaluation ◽  
Net Profit ◽  
Business Entities ◽  
Results Management ◽  
Main Components ◽  
The Impact

The main purpose of any enterprise in the market economy is to obtain high financial results. One of the main conditions for the effective functioning of the enterprise is ability to generate profit in the amount that will create the financial basis for further development and expansion of the enterprise, comply with social and material needs, ensure competitiveness in the market of goods and services. The need for accounting and analytical management of financial results stems from needs of owners, the state and employees in information that will enable them to identify patterns and trends in financial results, identify and assess the main factors influencing the process of their creation, distribution and usage, identify reserves and thus increase the level of profitability. Despite the significant scientific contribution in the field of research of financial results of the enterprises, the issue of improvement aims to the accounting and analytical maintenance of management of financial results of the enterprise remains actual. That is why the purpose of the study is to substantiate the theoretical and practical aspects and develop approaches to improving the mechanism of formation of accounting and analytical support for the management of financial results of the enterprise. Accounting and analytical management of financial results of the enterprise is a set of interconnected elements of production and management system, activities carried out by the subject of management, creation of a certain structure, as well as collection, accumulation, storage and analysis of information necessary for effective operation of the enterprise. The main components of the study of accounting and analytical support of financial performance management are the formation of methods of analysis, control and forecasting of financial results, which requires specification of the components of the analytical and controlled process within the organizational and information model. Namely, the formation of reliable information about the financial condition of the enterprise, the analysis of economic indicators of the enterprise is of great importance in the system of general evaluation of business entities. Their research makes it possible to assess the dynamics of the structure of income and expenses, to determine the impact of factors on the company's profit from various activities, as well as to find reserves to increase the net profit of enterprises. Thus, the improvement of accounting and analytical support of enterprise management is based on the use of modern forms, methods and principles that place new demands on the formation of unbiased, complete, timely, clear and useful accounting and analytical information about the enterprise and its financial results.

TEACH-POT: Provide Opportunities in Teaching

2020 ◽  
pp. 79-91 ◽  
Author(s):  
Maria Giulia Ballatore ◽  
Ettore Felisatti ◽  
Laura Montanaro ◽  
Anita Tabacco
Keyword(s):  
Academic Community ◽  
Real Effect ◽  
The Real ◽  
Main Components ◽  
The Impact ◽  
Training Opportunities ◽  
Different Levels

This paper is aimed to describe and critically analyze the so-called "TEACHPOT" experience (POT: Provide Opportunities in Teaching) performed during the last few years at Politecnico di Torino. Due to career criteria, the effort and the time lecturers spend in teaching have currently undergone a significant reduction in quantity. In order to support and meet each lecturers' expectations towards an improvement in their ability to teach, a mix of training opportunities has been provided. This consists of an extremely wide variety of experiences, tools, relationships, from which everyone can feel inspired to increase the effectiveness of their teaching and the participation of their students. The provided activities are designed around three main components: methodological training, teaching technologies, methodological experiences. A discussion on the findings is included and presented basing on the data collected through a survey. The impact of the overall experience can be evaluated on two different levels: the real effect on redesigning lessons, and the discussion on the matter within the entire academic community.

FORMATION OF HUMAN CAPITAL IN THE DIGITAL TRANSFORMATION PARADIGM

2020 ◽  
Vol 2 (5) ◽  
pp. 115-119
Author(s):  
M. V. SAVINA ◽  
◽  
A. A. STEPANOV ◽  
I.A. STEPANOV ◽  
◽  
...  
Keyword(s):  
Human Capital ◽  
Digital Age ◽  
Digital Transformation ◽  
Educational Process ◽  
Knowledge And Skills ◽  
Main Components ◽  
The Impact ◽  
Modern Era

The article highlights the problems of the impact of "digitalization" of society on the formation and transformation of human capital, and above all, the development of new competencies, knowledge and skills. The main components of human capital in the modern era, the features of the formal and informal educational process are clarified and disclosed. The necessity of minimizing the precariat class is proved. The main directions of qualitative improvement of human capital adequate to the challenges of the digital age and globalization are defined.

scholarly journals Dynamics of the rumor-spreading model with hesitation mechanism in heterogenous networks and bilingual environment

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Shuai Yang ◽  
Haijun Jiang ◽  
Cheng Hu ◽  
Juan Yu ◽  
Jiarong Li
Keyword(s):  
Lyapunov Method ◽  
Reproduction Number ◽  
Model Parameters ◽  
Rumor Spreading ◽  
Spreading Model ◽  
Reductio Ad Absurdum ◽  
The Stability ◽  
The Impact ◽  
Theoretical Results ◽  
The Basic Reproduction Number

Abstract In this paper, a novel rumor-spreading model is proposed under bilingual environment and heterogenous networks, which considers that exposures may be converted to spreaders or stiflers at a set rate. Firstly, the nonnegativity and boundedness of the solution for rumor-spreading model are proved by reductio ad absurdum. Secondly, both the basic reproduction number and the stability of the rumor-free equilibrium are systematically discussed. Whereafter, the global stability of rumor-prevailing equilibrium is explored by utilizing Lyapunov method and LaSalle’s invariance principle. Finally, the sensitivity analysis and the numerical simulation are respectively presented to analyze the impact of model parameters and illustrate the validity of theoretical results.

Models for New Corrugated and Porous Solar Air Collectors under Transient Operation

2017 ◽  
Vol 42 (1) ◽  
Author(s):  
Qahtan Adnan Abed ◽  
Viorel Badescu ◽  
Adrian Ciocanea ◽  
Iuliana Soriga ◽  
Dorin Bureţea
Keyword(s):  
Climatic Conditions ◽  
Meteorological Conditions ◽  
Bias Error ◽  
First Order ◽  
Solar Air Collector ◽  
Section Surface ◽  
South Eastern Europe ◽  
Main Components ◽  
Theoretical Results ◽  
Good Agreement

AbstractMathematical models have been developed to evaluate the dynamic behavior of two solar air collectors: the first one is equipped with a V-porous absorber and the second one with a U-corrugated absorber. The collectors have the same geometry, cross-section surface area and are built from the same materials, the only difference between them being the absorbers. V-corrugated absorbers have been treated in literature but the V-porous absorbers modeled here have not been very often considered. The models are based on first-order differential equations which describe the heat exchange between the main components of the two types of solar air heaters. Both collectors were exposed to the sun in the same meteorological conditions, at identical tilt angle and they operated at the same air mass flow rate. The tests were carried out in the climatic conditions of Bucharest (Romania, South Eastern Europe). There is good agreement between the theoretical results and experiments. The average bias error was about 7.75 % and 10.55 % for the solar air collector with “V”-porous absorber and with “U”-corrugated absorber, respectively. The collector based on V-porous absorber has higher efficiency than the collector with U-corrugated absorber around the noon of clear days. Around sunrise and sunset, the collector with U-corrugated absorber is more effective.

On the Evaluation and Consideration of Fracture Mechanical Notch Support Within a Creep Fatigue Lifetime Assessment

2018 ◽  
Author(s):  
Christian Kontermann ◽  
Henning Almstedt ◽  
Falk Müller ◽  
Matthias Oechsner
Keyword(s):  
Fatigue Loading ◽  
Experimental Program ◽  
Energy Market ◽  
Steam Turbines ◽  
Fatigue Lifetime ◽  
Global Strain ◽  
Creep Fatigue ◽  
Main Components ◽  
Flexible Operation ◽  
The Impact

Changes within the global energy market and a demand for a more flexible operation of gas- and steam-turbines leads to higher utilization of main components and raises the question how to deal with this challenge. One strategy to encounter this is to increase the accuracy of the lifetime assessment by quantifying and reducing conservatisms. At first the impact of considering a fracture mechanical notch support under creep-fatigue loading is studied by discussing the results of an extensive experimental program performed on notched round-bars under global strain control. A proposal how to consider this fracture mechanical notch support within a lifetime assessment is part of the discussion of the second part. Here, a theoretical FEM-based concept is introduced and validated by comparing the theoretical prediction with the results of the previously mentioned experimental study. Finally, the applicability of the developed and validated FEM-based procedure is demonstrated.

SILICON ON RAISED INSULATOR FIELD EFFECT DIODE (SORI-FED) FOR ALLEVIATING SCALING PROBLEM IN FED

2014 ◽  
Vol 28 (05) ◽  
pp. 1450038 ◽  
Author(s):  
MAHDI VADIZADEH ◽  
MORTEZA FATHIPOUR ◽  
GHAFAR DARVISH
Keyword(s):  
Delay Time ◽  
Field Effect ◽  
Channel Length ◽  
Gate Delay ◽  
Electrical Characteristics ◽  
Band To Band Tunneling ◽  
Main Components ◽  
Channel Lengths ◽  
Length Scaling ◽  
The Impact

One of the main shortcomings in a field effect diode (FED) is its scaling. Use of an oxide layer in the channel is proposed to enhance the control of the gate on the channel carriers. This is the so-called silicon on raised insulator FED (SORI-FFD) structure. The Shockley–Read–Hall (SRH) mechanism is one of the main components of leakage current in FED devices. The potential induced by the gates in the OFF-state of a SORI-FFD, is larger than that induced by the gates of a regular FED. This reduces, SRH recombination rate. Hence, OFF-state characteristics of the SORI-FED device improves. We evaluate the impact of band-to-band tunneling (BTBT) on the electrical characteristics of Modified FED (M-FED).We show that for channel lengths of 35 nm and lower this device does not turn off. While, the proposed structure makes device channel length scaling possible down to 15 nm. We will also compare electrical characteristics of SORI-FED and M-FED using three metrics: gate delay time versus channel length, gate delay time versus I ON /I OFF ratio and energy-delay product versus channel length. Benchmarking results show the proposed FED structure provides improvement in I ON /I OFF ratio and holds promise for future logic transistor applications.

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