scholarly journals A Time-Domain Substructure Synthesis for Finite Rotations of Flexible Mechanical Systems

2017 ◽  
Author(s):  
Chen Shulin ◽  
Liu Li ◽  
Chen Zhaoyue
Keyword(s):  
Time Domain ◽  
Mechanical Systems ◽  
Finite Rotations ◽  
Substructure Synthesis

A Time Domain Substructure Synthesis Method for Viscoelastic Structures

1995 ◽  
Vol 62 (2) ◽  
pp. 407-413 ◽  
Author(s):  
Duan Qian ◽  
J. S. Hansen
Keyword(s):  
Time Domain ◽  
Synthesis Method ◽  
Integral Form ◽  
Viscoelastic Damping ◽  
Substructure Synthesis ◽  
Viscoelastic Models ◽  
Hereditary Integral ◽  
Space Formulation ◽  
The Time Domain ◽  
Damped Systems

The method of substructure synthesis, originally conceived for undamped and viscously damped systems, has been extended to systems with viscoelastic damping in the hereditary integral form. Based on a new variational principle, the substructure synthesis method is formulated in the time domain. The displacement in each substructure is represented by a set of real admissible trial vectors. The traditional state space formulation is avoided by the proposed method so that the approach is independent of the form of viscoelastic models. Effectiveness of the method is illustrated through numerical examples.

Modified HHT Method for Vehicle Vibration Analysis in Time Domain Utilisation

2013 ◽  
Vol 486 ◽  
pp. 396-405 ◽  
Author(s):  
Juraj Gerlici ◽  
Tomáš Lack
Keyword(s):  
Mechanical System ◽  
Time Domain ◽  
Vibration Analysis ◽  
Mechanical Systems ◽  
Dynamical Analysis ◽  
Vehicle Design ◽  
Negative State ◽  
Eigen Frequencies ◽  
Dynamical Properties

The analysis of mechanical systems (for example the mechanical systems of vehicles) vibration is permanently very topical. The vehicle dynamical properties are determined with the help of this analysis during a new vehicle design, or renewal of an older existing vehicle. The Eigen frequencies are characteristic for a vehicle construction. A vehicle mechanical system is excited with various types of loads in the operation and this is the reason why its individual parts oscillate. The aim of a dynamical analysis is not only to judge the influence of an excitation on the mechanical system, but also on the base of that analysis, to propose and to perform the construction changes of a vehicle for the detected negative state elimination or improvement.

Time-Domain Substructure Synthesis with Hybrid Rigid and Nonlinear-Elastic Joints

AIAA Journal ◽  
2016 ◽  
Vol 54 (8) ◽  
pp. 2545-2551 ◽  
Author(s):  
Si-Da Zhou ◽  
Li Liu ◽  
Wei-Li Dong
Keyword(s):  
Time Domain ◽  
Substructure Synthesis ◽  
Elastic Joints ◽  
Nonlinear Elastic

scholarly journals How to Experimentally Monitor the Fatigue Behaviour of Vibrating Mechanical Systems?

2020 ◽  
Vol 66 (10) ◽  
pp. 557-566
Author(s):  
Filippo Cianetti
Keyword(s):  
Mechanical System ◽  
Fatigue Damage ◽  
Time Domain ◽  
Residual Life ◽  
Numerical Models ◽  
A Priori ◽  
Mechanical Systems ◽  
Signal Amplitude ◽  
Fatigue Behaviour ◽  
Operational Life

Fatigue damage and, in general, fatigue behaviour is not simple to observe or estimate during the operational life of a generic vibrating mechanical system. There are a lot of theoretical or numerical methods that allow to evaluate it or by knowing a priori the loading conditions and obtaining output stress states by adopting numerical models of the mechanical system or by directly experimentally measuring and acquiring stress/strain states. A few examples of instruments (e.g. rain flow recorders) or measurement chains dedicated to estimate it in time domain or frequency domain are found in the literature but none that fully both observes the system dynamic behaviour and estimates the related actualized cumulated damage, and, thus, none that can estimate the residual life of the system itself. In this paper, a simple time-domain method, designed to monitor the instantaneous fatigue behaviour by definition of the instantaneous and cumulated potential damage or of equivalent damage signal amplitude is presented, based on rain-flow counting method and a damage linear cumulation law and starting from system dynamics signals. This methodology was designed to overestimate real damage to alert the system manager before any crack starts and to be simply translated into electronic boards that can be mounted on generic mechanical systems and linked to one of the sensors that usually monitor system functionality. Keywords: fatigue; damage; rain flow counting; random loads

A Time and Frequency Domain Approach for Identifying Non-Linear Automotive Suspension System Models in the Absence of an Input Measurement

2004 ◽  
Author(s):  
Muhammad Haroon ◽  
Douglas E. Adams ◽  
Yiu Wah Luk ◽  
Aldo A. Ferri
Keyword(s):  
System Identification ◽  
Frequency Domain ◽  
Time Domain ◽  
Nonlinear System Identification ◽  
Mechanical Systems ◽  
Suspension System ◽  
Restoring Force ◽  
Automotive Suspension ◽  
The Time Domain ◽  
Vehicle Suspension System

The inputs to many ‘real’ mechanical systems are not readily measurable. For example, the input to the tire patch of the tires of automotive road vehicles is neither measurable nor easy to estimate. As conventional system identification procedures require input measurements or at least estimates of the inputs, a new approach for nonlinear system identification of mechanical systems, in the absence of an input measurement, is presented here. This approach uses a combination of time domain (Restoring Force) and frequency domain (Nonlinear Identification through Feedback of the Outputs (NIFO)) techniques. The time domain is used to characterize the nonlinearities in the system and the observed nonlinear characteristics are used in the frequency domain to build a model of the system. The method is applied to experimental tire-vehicle suspension system data.

Substructure Synthesis in Time Domain with Rigid–Elastic Hybrid Joints

AIAA Journal ◽  
2015 ◽  
Vol 53 (2) ◽  
pp. 504-510 ◽  
Author(s):  
Wei-Li Dong ◽  
Li Liu ◽  
Si-Da Zhou ◽  
Shu-Lin Chen
Keyword(s):  
Time Domain ◽  
Substructure Synthesis ◽  
Hybrid Joints

Time-Domain Dynamic Analysis of Piezoelectric MLA

2010 ◽  
Author(s):  
Paolo Righettini ◽  
Mauro Forlani ◽  
Roberto Strada
Keyword(s):  
Time Domain ◽  
Dynamic Behaviour ◽  
Mechanical Systems ◽  
Electric Circuit ◽  
Transient Phenomena ◽  
Step Voltage ◽  
Linear Behaviour ◽  
High Dynamic ◽  
Finite Difference Techniques ◽  
Multilayer Actuators

Piezoelectric multilayer actuators (MLAs) are among the most suitable piezoelectric actuators to be integrated into fast mechanical systems, given their high force capabilities and high dynamic response. Overall dynamic behaviour though is influenced by load and driving electric circuit characteristics. The aim of the present work is to investigate the transient dynamics of mechanical systems actuated by MLAs. To this purpose, the system, including the driving electric circuit, is modelled employing finite difference techniques. Such methods are extremely flexible and allow modelling non-linear behaviour and transient phenomena. In particular the response to an input step voltage will be simulated and the influence of the system’s parameters on its response will be investigated. The results provide valuable information such as required currents that can help the engineer in the design process.

Sign in / Sign up

Export Citation Format

Share Document