Influence of the Interaction Yield Domain on Lateral-Torsional Coupling of Asymmetric Single-Storey Systems

2016 ◽  
pp. 205-214 ◽  
Author(s):  
Melina Bosco ◽  
Aurelio Ghersi ◽  
Edoardo M. Marino ◽  
Pier Paolo Rossi
Keyword(s):  
Torsional Coupling

Torsional Coupling and Earthquake Response of Simple Elastic and Inelastic Systems

1981 ◽  
Vol 107 (8) ◽  
pp. 1569-1588 ◽  
Author(s):  
Christopher L. Kan ◽  
Anil K. Chopra
Keyword(s):  
Earthquake Response ◽  
Torsional Coupling

Stick slip characteristics analysis of drill string system with longitudinal and torsional coupling tool

2021 ◽  
pp. 1-18
Author(s):  
Jialin Tian ◽  
Gang Liu ◽  
Haolin Song ◽  
Chenghang Liu ◽  
Feng Wen
Keyword(s):  
Drill String ◽  
Stick Slip ◽  
Characteristics Analysis ◽  
Torsional Coupling

Free Vibration Analysis of Two-Stage Planetary Gear With Friction

2018 ◽  
Author(s):  
Wei Liu ◽  
Yunbo Yuan ◽  
Tao He ◽  
Donghua Wang
Keyword(s):  
Free Vibration ◽  
Degrees Of Freedom ◽  
Sliding Friction ◽  
Free Vibration Analysis ◽  
Planetary Gear ◽  
Two Stage ◽  
Second Stage ◽  
Torsional Coupling ◽  
Coupling Dynamic ◽  
First Time

Considering the effect of teeth surface sliding friction, free vibration of two-stage planetary gears (TPG) is studied theoretically for the first time. The lateral-torsional coupling dynamic model and equation are established with three degrees of freedom: two translations and one rotation. The change rule of natural frequency is discussed with the case of first stage planetary gear’s number 4 and second stage planetary gear’s number 3, 4 and 5. Afterwards three vibration modes are summarized by calculating the free vibration. In order to understand the behavior of friction, the effect of friction on natural frequencies is analyzed for the case of considering friction and not considering friction. Furthermore, the ‘self-coupling’ phenomenon is obtained from the vibration of center component of TPG Meanwhile, the ‘mutual coupling’ is obtained between the first-stage planetary gear (FPG) and the second-stage planetary gear (SPG).

Nonlinear characteristics of a multi-degree-of-freedom spur gear system with bending-torsional coupling vibration

2019 ◽  
Vol 121 ◽  
pp. 810-827 ◽  
Author(s):  
Junguo Wang ◽  
Jie Zhang ◽  
Zhaoyuan Yao ◽  
Xufeng Yang ◽  
Rui Sun ◽  
...  
Keyword(s):  
Spur Gear ◽  
Degree Of Freedom ◽  
Gear System ◽  
Nonlinear Characteristics ◽  
Coupling Vibration ◽  
Torsional Coupling

scholarly journals Metamodel Approaches in Predicting the Seismic Response of Asymmetric Buildings

2021 ◽  
Author(s):  
Philip Luke Karuthedath ◽  
Deepak Sahu ◽  
Robin Davis P
Keyword(s):  
Seismic Response ◽  
Computational Effort ◽  
High Dimensional Model Representation ◽  
Centre Of Mass ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Asymmetric Buildings ◽  
Torsional Coupling ◽  
Computationally Intensive ◽  
Free Vibration Response

Asymmetry formed as a result of the eccentricity between the positions of Centre of Mass and Centre of Stiffness can cause undesired torsional coupling and can weaken the seismic performance of buildings and structures. This dynamic response is further affected by the randomness in material, geometric and loading properties caused as a result of uncertainties in construction and functioning. Stochastic analyses methods such as Monte Carlo Simulation have been found to accurately characterize this randomness and uncertainty, but are computationally intensive as well as expensive. This necessitates the need for alternative analyses methods that are much simpler and can fairly represent the uncertainties while preserving the similarity in results. The present investigation considers the various metamodel approaches in non-statistical stochastic analyses methods in determining the seismic response of asymmetric buildings. The study observes the efficiency of the High Dimensional Model Representation (HDMR) approach in accurately predicting the free vibration response of a reinforced concrete frame with the least number of samplings points as well as computational effort as compared to other response surface methods. For further validation, a non-linear reliability analysis was carried out at HDMR sampling points to obtain the seismic fragility of the building considered, the results of which satisfied the fragility obtained using conventional methods.

A new torsional vibration coupling model for transmission system in diesel generator

2021 ◽  
pp. 146808742110689
Author(s):  
Bin Chen ◽  
Yunbo Hu ◽  
Yibin Guo ◽  
Zhijun Shuai ◽  
Chongpei Liu ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Torsional Vibration ◽  
Coupling Model ◽  
Transmission System ◽  
System Matrix ◽  
Diesel Generator ◽  
Lumped Mass ◽  
Proposed Model ◽  
Torsional Coupling ◽  
Vibration Coupling

The coupling between the crankshaft and the camshaft is neglected before in fault diagnosis which may lead to incomplete fault information. In this paper, a new torsional coupling model of a diesel generator transmission system is proposed for fault diagnosis. The natural frequency and forced torsional vibration response of the model are obtained by the system matrix method and Newmark-β method. For the system without considering the lumped mass of camshafts, some key natural frequencies are lost. The vibration dynamics are compared for the transmission system with and without the new coupling model. And important frequency responses are missed in the spectrums of the forced torsional vibration without the new coupling model. Finally, the new coupling model is implemented in fault diagnosis and the cause of an unusual vibration fault is deduced in the simulation, which confirms the feasibility of the proposed model in fault diagnosis.

scholarly journals Bending–torsional-coupled vibrations and buckling characteristics of single and double composite Timoshenko beams

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983445
Author(s):  
Ma’en S Sari ◽  
Wael G Al-Kouz ◽  
Rafat Al-Waked
Keyword(s):  
Slenderness Ratio ◽  
Equations Of Motion ◽  
Mode Shapes ◽  
Timoshenko Beams ◽  
Engineering Structures ◽  
Axial Forces ◽  
Double Beam ◽  
Tensile Forces ◽  
Torsional Coupling ◽  
The Stability

The stability and free vibration analyses of single and double composite Timoshenko beams have been investigated. The closed-section beams are subjected to constant axially compressive or tensile forces. The double beams are assumed to be connected by a layer of elastic translational and rotational springs. The coupled governing partial differential equations of motion are discretized, and the resulted eigenvalue problem is solved numerically by applying the Chebyshev spectral collocation method. The effects of the elastic layer parameters, the axial forces, the slenderness ratio, the bending–torsional coupling, and the boundary conditions on the critical buckling loads, mode shapes, and natural transverse frequencies have been studied. A parametric study was performed, and the obtained results revealed different features, which hopefully can be useful for single- and double-beam-like engineering structures.

On the Axial-Flexural-Torsional Coupling of Underwater Slender Cylinders

2012 ◽  
Author(s):  
Waldir T. Pinto ◽  
Carlos A. Levi
Keyword(s):  
Large Strains ◽  
Element Formulation ◽  
Algebraic Equations ◽  
Three Dimensional Model ◽  
Cylindrical Structures ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Torsional Coupling ◽  
Lift Forces ◽  
Drag And Lift

This paper presents a numerical model for the simulation of the axial-flexural-torsional coupling of undewater cylindrical structures. Cylindrical structures are largely utilized in the marine environment in a wide range of applications as in risers, marine cables, flexible pipes, mooring systems and so on. They may exhibit complex axial-flexural-torsional coupling, which makes the structural analysis highly nonlinear. In addition, the fluid-structure interaction may include flow induced vibrations, frequency lock-in and internal flow effects. The proposed three-dimensional model assumes that the structure aspect ratio is very high, its cross section is circular, the cable is elastic and may experience large displacements and large strains, as long as the elastic regime holds. The steady state load on the cylinder consists of the self-weight and buoyancy, drag and lift forces, in addition to a distributed residual twist along the cylinder. The drag and lift forces are evaluated by Morison type formulation. The governing differential equations are derived from first principles, assuming Newtonian mechanics. Then, they are solved numerically by a finite element formulation based on nonlinear space frame elements. The resulting set of algebraic equations is solved by a minimization technique that uses the Newton-Raphson algorithm. Results show the ability of the model to predict the static configuration of equilibrium of the cylinder and to capture the coupling between axial, flexural and torsional responses of the cylinder.

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