Exact solutions of steady-state dynamic responses of a laminated composite double-beam system interconnected by a viscoelastic layer in hygrothermal environments

2021 ◽  
pp. 113939
Author(s):  
Bo Chen ◽  
Baichuan Lin ◽  
Yinghui Li ◽  
Huaiping Tang
Keyword(s):  
Steady State ◽  
Exact Solutions ◽  
Laminated Composite ◽  
Dynamic Responses ◽  
Viscoelastic Layer ◽  
State Dynamic ◽  
Beam System ◽  
Double Beam ◽  
Hygrothermal Environments

Dynamic Analysis of Helical Planetary Gear Train

2013 ◽  
Vol 404 ◽  
pp. 312-317 ◽  
Author(s):  
Xian Zeng Liu ◽  
Jun Zhang
Keyword(s):  
Steady State ◽  
Free Vibration ◽  
Dynamic Model ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Design Parameters ◽  
Planetary Gear Train ◽  
State Dynamic ◽  
The Impact

A dynamic model for helical planetary gear train (HPGT) is proposed. Based on the model, the free vibration characteristics, steady-state dynamic responses and effects of design parameters on system dynamics are investigated through numerical simulations. The free vibration of the HGPT is classified into 3 categories. The classified vibration modes are demonstrated as axial translational and torsional mode (AT mode), radial translational and rotational mode (RR mode) and planet mode (P mode) followed by the characteristics of each category. The simulation results agree well with those of previous discrete model when neglecting the component flexibilities, which validates the correctness of the present dynamic model. The steady-state dynamic responses indicate that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is one of the major excitations of the system. The parametric sensitivity analysis shows that the impact of the central component bearing stiffness on the dynamic characteristic of the HPGT system is significant.

scholarly journals Dynamic response of double-beam system with nonlinear viscoelastic layer to moving load

2018 ◽  
Vol 211 ◽  
pp. 11008 ◽  
Author(s):  
Piotr Koziol ◽  
Rafał Pilecki
Keyword(s):  
Moving Load ◽  
Equations Of Motion ◽  
Viscoelastic Layer ◽  
Nonlinear Stiffness ◽  
Viscoelastic Foundation ◽  
Dynamic Features ◽  
Beam System ◽  
Nonlinear Viscoelastic ◽  
Double Beam ◽  
Error Index

In previous papers, the problem of double-beam system resting on viscoelastic foundation was solved with the assumption of nonlinear foundation stiffness. This multilayer model finds application in railway modelling, where rails are represented by the infinite Euler-Bernoulli beams and sleepers are modelled as a rigid body. In this paper, another assumption is made. The layer connecting two Euler-Bernoulli beams has nonlinear stiffness. This assumption is related to laboratory tests of fastening systems. These tests show that the stiffness of fasteners and rail pads is nonlinear and this factor should be taken into account in detailed analysis of dynamic features. Therefore inclusion of nonlinearity in double-beam system is justified. The physical model presented in this paper consists of two infinitely long beams connected by viscoelastic layer with nonlinear stiffness and resting on viscoelastic foundation. The mathematical model is described by two coupled fourth order partial differential equations of motion with homogeneous boundary conditions. The system is solved by using the Fourier transform and Adomian’s decomposition, combined with the wavelet based approximation of the response using Coiflet filters. The error index for Adomian series is proposed and the approximate solution for vertical vibrations is shown along with computational examples for some systems of parameters.

Speech Perception in Adult Subjects With Familial Dyslexia

1992 ◽  
Vol 35 (1) ◽  
pp. 192-200 ◽  
Author(s):  
Michele L. Steffens ◽  
Rebecca E. Eilers ◽  
Karen Gross-Glenn ◽  
Bonnie Jallad
Keyword(s):  
Steady State ◽  
Speech Perception ◽  
Synthetic Speech ◽  
Acoustic Cues ◽  
State Dynamic ◽  
Spectral Cues ◽  
Temporal Cues ◽  
Familial Dyslexia ◽  
Overall Performance

Speech perception was investigated in a carefully selected group of adult subjects with familial dyslexia. Perception of three synthetic speech continua was studied: /a/-//, in which steady-state spectral cues distinguished the vowel stimuli; /ba/-/da/, in which rapidly changing spectral cues were varied; and /sta/-/sa/, in which a temporal cue, silence duration, was systematically varied. These three continua, which differed with respect to the nature of the acoustic cues discriminating between pairs, were used to assess subjects’ abilities to use steady state, dynamic, and temporal cues. Dyslexic and normal readers participated in one identification and two discrimination tasks for each continuum. Results suggest that dyslexic readers required greater silence duration than normal readers to shift their perception from /sa/ to /sta/. In addition, although the dyslexic subjects were able to label and discriminate the synthetic speech continua, they did not necessarily use the acoustic cues in the same manner as normal readers, and their overall performance was generally less accurate.

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