Synthesis of a class of linear mass-spring systems having prescribed transfer functions

1974 ◽  
Vol 32 (4) ◽  
pp. 433-441
Author(s):  
A.G.J. Holt
2014 ◽  
Vol 983 ◽  
pp. 420-423
Author(s):  
Sheng Guo Zhang ◽  
Xiao Ping Dang

This paper aims at directly modeling the transfer functions of mass-spring-damper systems. Using complex stiffness of mass, spring, and damper elements and equivalent complex stiffness of these elements in series and/or in parallel, the transfer functions of the mass-spring-damper systems are modeled quickly. This is very convenient to the modeling of the complicated mechanical systems.


2018 ◽  
Vol 241 ◽  
pp. 01004
Author(s):  
Sara Baghdadi ◽  
Faouzi Lakrad ◽  
Mohamed Belhaq

In the present work, we study the nonlinear vibrations of an AFM system, modeled as a linear mass-spring-damper system, under the Derjaguin-Muller-Toporov forces and subject to imposed slow harmonic base displacement. The invariant slow manifolds of the system are approximated and their bifurcations are investigated. Then, the charts of behaviors of the different operating modes of the AFM are determined. The dynamic saddle-node bifurcations of the contact and the noncontact invariant slow manifolds are found to be responsible for the occurrence of the tapping mode.


2021 ◽  
pp. 107754632110034
Author(s):  
Payam Soltani ◽  
Arnaud Deraemaeker

This study deals with the optimisation of pendulum tuned mass damper parameters for different types of excitations and responses of the host structure to which it is attached. The study considers force excitation and base excitation with different types of output quantities to be minimised on the host structure. It also considers both harmonic motion with H ∞ optimisation of the different transfer functions and random white noise excitation where the variance of the output signal is minimised, leading to H2 optimisation. Although a lot of work has been done on optimisation of tuned mass dampers, there exists in the literature only a few solutions for optimisation of the pendulum tuned mass dampers not covering all possible types of loads and output quantities. The analogy between the mass spring tuned mass damper and pendulum tuned mass damper presented in this study allows to use all the tuning rules developed for tuned mass dampers in the case of pendulum tuned mass dampers. In addition, the existing tuning rules for tuned mass dampers are extended to cases which were not previously solved in the literature for H2 optimisation and validated by comparing with numerical optimisation. Finally, a discussion is presented where the different tuning rules are compared, and the performance degradation is assessed when the wrong tuning rule is used. This is representative of the case where, for example, both wind and earthquake excitation exist on the structure, and the pendulum tuned mass damper is tuned for just wind excitation.


2005 ◽  
Vol 128 (2) ◽  
pp. 229-234 ◽  
Author(s):  
Il-Kyu Hwang ◽  
Kyu-Jung Kim ◽  
Kenton R. Kaufman ◽  
William P. Cooney ◽  
Kai-Nan An

Despite the use of wrist guards during skate- and snowboard activities, fractures still occur at the wrist or at further proximal locations of the forearm. The main objectives of this study were to conduct a human subject testing under simulated falling conditions for measurement of the impact force on the hand, to model wrist guards as a shock isolator, to construct a linear mass-spring-damper model for quantification of the impact force attenuation (Q-ratio) and energy absorption (S-ratio), and to determine whether wrist guards play a role of an efficient shock isolator. While the falling direction (forward and backward) significantly influenced the impact responses, use of wrist guards provided minimal improvements in the Q- and S-ratios. It was suggested based on the results under the submaximal loading conditions that protective functions of the common wrist guard design could be enhanced with substantial increase in the damping ratio so as to maximize the energy absorption. This would bring forth minor deterioration in the impact force attenuation but significant increase in the energy absorption by 19%, which would help better protection against fall-related injuries of the upper extremity.


2002 ◽  
Vol 21 (1) ◽  
pp. 85-100 ◽  
Author(s):  
Marc H.E. de Lussanet ◽  
Jeroen B.J. Smeets ◽  
Eli Brenner
Keyword(s):  

Author(s):  
William Durfee ◽  
Perry Li ◽  
David Walezko

At-home laboratories are inexpensive hardware kits that students take home and work on much like a problem set. The kits have an embedded microcontroller and communicate to the student’s home PC over a serial port. The home PC provides the needed computational horsepower for experiment control, data collection, data analysis and reporting. The microcontroller handles real-time control tasks. Two first-generation kits were developed, a fourth-order, linear mass-spring-damper system for frequency response and system identification, and an analog filtering system that uses music and synthetic sound as an input for understanding the properties of analog filters. Twenty five kits were constructed and used by students. Based on this pilot, improved, second generation kits have been designed.


1956 ◽  
Vol 60 (549) ◽  
pp. 620-621 ◽  
Author(s):  
J. P. Ellington ◽  
H. McCallion

A solution, in terms of known integrals, is obtained for the motion from rest of a machine, idealised as an undamped linear mass-spring system, when subjected to an exciting force whose frequency varies at a constant rate.In many installations of modern high speed machinery the running speed of the machine is in excess of the resonant or natural frequency of the system, and consequently starting up or stopping the machine could result in vibrations of large amplitude. The problem of assessing the magnitude and duration of these vibrations is very complicated and has been solved analytically only for the case of a single degree of freedom system excited by an oscillating force whose frequency varies linearly with time. However, even this solution is not easy to evaluate, the integrals involved demanding either graphical construction and numerical integration or summation of series.


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