The analysis of dynamic fracture using lumped mass-spring models

1987 ◽  
Vol 33 (1) ◽  
pp. 47-59 ◽  
Author(s):  
J. G. Williams
Keyword(s):  
Dynamic Fracture ◽  
Lumped Mass ◽  
Mass Spring

Dynamic analysis and optimization of cutting mechanism about aluminum electrolytic capacitor casing machine

2016 ◽  
Vol 230 (4) ◽  
pp. 368-378
Author(s):  
Bizhong Xia ◽  
Shiyuan Ren ◽  
Xin Shang ◽  
Xincheng Liu
Keyword(s):  
Dynamic Performance ◽  
Electrolytic Capacitor ◽  
Lumped Mass ◽  
Cutting Mechanism ◽  
Bending Vibrations ◽  
Aluminum Electrolytic Capacitor ◽  
B Spline ◽  
Important Input ◽  
Cam Profile ◽  
Mass Spring

The dynamic characteristics and optimization of a cutting mechanism about aluminum electrolytic capacitor casing machine were investigated with a lumped mass-spring damper model in this paper. In the lumped mass-spring damper model, compliance of the links and effects of mechanism position on deformable transfer relationship are taken into account. Besides, torsional and bending vibrations of camshaft are also considered. Cam profile is an important input excitation of the cutting mechanism and has important influence on the dynamic performance. Therefore, optimization of cam profile was also studied based on the dynamic model and B-spline. Acceleration fluctuations were significantly reduced after the optimization.

Simulation Of Vocal Fold Oscillation Using A Lumped Mass-Spring Approach

1987 ◽  
Vol 7 (2) ◽  
pp. 62-67 ◽  
Author(s):  
D Wong ◽  
M.R. Ito ◽  
T Nicol
Keyword(s):  
Vocal Fold ◽  
Lumped Mass ◽  
Mass Spring

scholarly journals Indirect Inverse Substructuring Method for Multibody Product Transport System with Rigid and Flexible Coupling

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jun Wang ◽  
Li-xin Lu ◽  
Pengjiang Qian ◽  
Li-qiang Huang ◽  
Yan Hua ◽  
...  
Keyword(s):  
Transport System ◽  
Dynamic Equilibrium ◽  
Dynamic Stiffness ◽  
Measuring System ◽  
System Level ◽  
Lumped Mass ◽  
Component Level ◽  
Flexible Coupling ◽  
Coupling Dynamic ◽  
Mass Spring

The aim of this paper is to develop a new frequency response function- (FRF-) based indirect inverse substructuring method without measuring system-level FRFs in the coupling DOFs for the analysis of the dynamic characteristics of a three-substructure coupled product transport system with rigid and flexible coupling. By enforcing the dynamic equilibrium conditions at the coupling coordinates and the displacement compatibility conditions, a closed-form analytical solution to inverse substructuring analysis of multisubstructure coupled product transport system is derived based on the relationship of easy-to-monitor component-level FRFs and the system-level FRFs at the coupling coordinates. The proposed method is validated by a lumped mass-spring-damper model, and the predicted coupling dynamic stiffness is compared with the direct computation, showing exact agreement. The method developed offers an approach to predict the unknown coupling dynamic stiffness from measured FRFs purely. The suggested method may help to obtain the main controlling factors and contributions from the various structure-borne paths for product transport system.

Early phase modeling of frontal impacts for crashworthiness: From lumped mass–spring models to Deformation Space Models

2018 ◽  
Vol 233 (12) ◽  
pp. 3000-3015 ◽  
Author(s):  
Volker A Lange ◽  
Johannes Fender ◽  
Lailong Song ◽  
Fabian Duddeck
Keyword(s):  
Early Phase ◽  
Solution Space ◽  
Research Field ◽  
Deformation Space ◽  
Space Technology ◽  
Lumped Mass ◽  
Space Model ◽  
Frontal Impacts ◽  
Mass Spring ◽  
Simplified Modeling

Because of the drawbacks of standard lumped mass–spring models discussed at the beginning of this paper, a new approach for simplified modeling of frontal impacts appropriate for early phase crashworthiness design is proposed. It is based on a first step, the Geometry Space Model, representing the real location of the structural components with deformable, non-deformable, and gap parts. This is then transformed by a new algorithm into the Deformation Space Model which considers only the available free deformation lengths and can be used to assess the correct deformation modes of complex structural systems. These developments are embedded in a wider research field, already published, where Solution Spaces are established for set-based design of the force–displacement curves for all springs. Together with this Solution Space technology, the proposed new simplified modeling approach for frontal impacts will make early phase development more efficient in the future.

scholarly journals Study on Dynamic Interaction of Railway Pantograph–Catenary Including Reattachment Momentum Impact

Vibration ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 18-33 ◽  
Author(s):  
Wenping Chu ◽  
Yang Song
Keyword(s):  
Contact Force ◽  
Momentum Conservation ◽  
Time Instant ◽  
Contact Forces ◽  
Normal Operation ◽  
Sudden Increase ◽  
Lumped Mass ◽  
Contact Wire ◽  
Simulation Tools ◽  
Mass Spring

The pantograph–catenary system is responsible for the electric transmission to the locomotive via the sliding contact between the pantograph head and the contact wire. The separation of the pantograph head from the contact wire is the main source of arcing, which challenges the normal operation of an electrified railway. To properly describe the contact loss procedure using simulation tools, a mathematical model of the reattachment momentum impact between the pantograph head and the contact wire is proposed in this paper. The Euler–Bernoulli beam is adopted to model the contact and messenger wires, which are connected by lumped mass-spring droppers. The Lagrange multiplier method is utilised to describe the contact between the pantograph head and the contact wire. The momentum impact generated during the reattachment process is derived based on the principle of momentum conservation. Through several numerical simulations, the contact wire uplift and the contact force are evaluated with the reattachment impact. The analysis result indicated that the velocities of the contact wire and the pantograph head experience a sudden jump at the time instant of reattachment, which leads to a sudden increase of the contact force. When the reattachment impact is included, the maximum value and the standard deviation of contact forces show a significant increase. The effect of reattachment impact is more significant with the increase of the pantograph mass and stiffness.

Experimental Assessment of the Behaviour of a Pipe Vibration Damper Underwater

2014 ◽  
Author(s):  
Sergio N. Bordalo ◽  
Celso K. Morooka ◽  
Luan G. Tochetto ◽  
Renato Pavanello ◽  
Gangbing Song ◽  
...  
Keyword(s):  
Internal Flow ◽  
Small Scale ◽  
Water Tank ◽  
Lumped Mass ◽  
Elastic Suspension ◽  
Mass Damper ◽  
Static And Dynamic Loads ◽  
Mass Spring ◽  
The Impact ◽  
Pipe Vibration

Submarine petroleum pipelines, risers and jumpers suffer static and dynamic loads due to sea currents and waves, due to the displacements of the floating production units and due to the internal flow, among other causes. Mitigating the oscillations caused by such excitations is critical to the reliability and fatigue of those underwater bodies. The Pounding Tuned Mass Damper (PTMD) is one device that may be employed to absorb and dissipate vibrations. These devices have long been used for mechanical systems operating in the atmosphere, but are new for underwater applications. This paper presents a study of the behaviour of a PTMD working underwater. A small scale laboratory apparatus was built to assess the effect of the absorber on the oscillation of a pipe submerged in a water tank. The PTMD was attached to a test pipe section mounted on an elastic suspension harness. The PTMD model is a lumped mass-spring attachment similar to a tuned mass dumper (TMD) suppressor, but with the addition of a pounding layer, which limits the motion of the PTMD mass, dissipating the energy of the oscillating pipe through the impact of the PTMD mass against that layer. Free and forced oscillation experiments were executed in air and in water, with and without the oscillation absorber, to determine the effectiveness of the PTMD. The tests were run on a range of excitation frequencies and the amplification factors were obtained for each case. The data show a remarkable influence of the surrounding media on the dynamics of the pipe-absorber system, therefore the interaction with the water must be taken into consideration in the design of the system. Although the results are only a preliminary step on the development of a device applicable to an actual petroleum submarine pipeline, it was observed that the PTMD does indeed suppress the vibrations, but it must be properly configured to achieve an optimum performance. The data gathered from this work will also be useful in the improvement of a numerical model of the pipe-PTMD system for use in a computer simulator.

Dynamic Analysis on the H-Type Stage Using Largrange Method

2012 ◽  
Vol 542-543 ◽  
pp. 663-666
Author(s):  
Kyoungchon Kim ◽  
Dae Gab Gweon ◽  
Dong Pyo Hong ◽  
Byoungkuk Lee
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Modeling ◽  
Dynamic Performance ◽  
Settling Time ◽  
Positioning System ◽  
Precision Positioning ◽  
Lumped Mass ◽  
Lagrange Method ◽  
Spring System ◽  
Mass Spring

Dynamic performance in the H-type stage as precision positioning system is important specification to guarantee precise accuracy. As the range of the H-type stage has increased, the dynamic performance affects the settling time of the H-type stage. This article concentrates analysis of the dynamic modeling of the H-type stage with rotational flexure joint. The dynamic modeling of the H-type stage was analyzed using Lagrange method assumed as lumped mass-spring system. The dynamic modeling of the H-type stage was verified by the experiment.

scholarly journals Dynamic fracture of a dissimilar chain

2019 ◽  
Vol 377 (2156) ◽  
pp. 20190103 ◽  
Author(s):  
N. Gorbushin ◽  
G. Mishuris
Keyword(s):  
Steady State ◽  
Dynamic Fracture ◽  
Model Parameters ◽  
Static Case ◽  
Theme Issue ◽  
Double Chain ◽  
Structured Media ◽  
Applied Forces ◽  
Mass Spring ◽  
Dynamic Phenomena

In this paper, we study the dynamic fracture of a dissimilar chain composed of two different mass-spring chains and connected with other springs. The propagation of the fault (crack) is realized under externally applied moving forces. In comparison with a homogeneous double chain, the considered structure displays some new essential features of steady-state crack propagation. Specifically, the externally applied forces are of a different strength, unlike a static case, and should be appropriately chosen to satisfy the equilibrium of the structure. Moreover, there exists a gap in the range of crack speeds where the steady-state fracture cannot occur. We analyse the admissibility of solutions for different model parameters and crack speeds. We complement analytical findings with numerical simulations to validate our results. This article is part of the theme issue ‘Modelling of dynamic phenomena and localization in structured media (part 1)’.

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