scholarly journals Investigating the impact of the velocity of a vehicle with a nonlinear suspension system on the dynamic behavior of a Bernoulli–Euler bridge

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Babak Shafiei
Keyword(s):  
Dynamic Response ◽  
Dynamic Behavior ◽  
Numerical Models ◽  
Closed Form Solution ◽  
Suspension System ◽  
Superposition Method ◽  
Nonlinear Stiffness ◽  
Moving Vehicle ◽  
Stiffness And Damping ◽  
The Impact

AbstractSeveral authors, utilizing both experimental tests and complicated numerical models, have investigated vehicle speed's impact on a highway bridge's dynamic amplification. Although these tests and models provide reliable quantitative data on frequency contents of the interaction between the two subsystems, engineers should pay further notice to the effects of a subsystem's velocity and the type of suspension system of a vehicle moving over a structure. Hence, in this paper, the dynamic response of a bridge to a moving vehicle is considered. The car is assumed as a quarter car model with both linear and nonlinear stiffness and damping constants. Further, using the modal superposition method, a closed-form solution is obtained for the bridge's vertical response. The results obtained via numerical calculation show a significant increase in the bridge midpoint and total deflection, velocity, and acceleration by increasing the vehicle velocity. Moreover, by neglecting the nonlinear stiffness and damping coefficients of the vehicle suspension system, the bridge's dynamic response remains almost the same with respect to the numerical data. As a general conclusion, it can be claimed that the only significant parameters which can change the dynamic behavior of a bridge subjected to a moving vehicle are the speed of the car and its linear stiffness and damping constants inside its suspension system.

Influence of the backlash generated by tooth accumulated wear on dynamic behavior of compound planetary gear set

2016 ◽  
Vol 231 (11) ◽  
pp. 2025-2041 ◽  
Author(s):  
Shijing Wu ◽  
Haibo Zhang ◽  
Xiaosun Wang ◽  
Zeming Peng ◽  
Kangkang Yang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Planetary Gear ◽  
Tooth Wear ◽  
Transmission Error ◽  
Gear Transmission ◽  
Tooth Surface ◽  
Contact Ratio ◽  
The Impact

Backlash is a key internal excitation on the dynamic response of planetary gear transmission. After the gear transmission running for a long time under load torque, due to tooth wear accumulation, the backlash between the tooth surface of two mating gears increases, which results in a larger and irregular backlash. However, the increasing backlash generated by tooth accumulated wear is generally neglected in lots of dynamics analysis for epicyclic gear trains. In order to investigate the impact of backlash generated by tooth accumulated wear on dynamic behavior of compound planetary gear set, in this work, first a static tooth surface wear prediction model is incorporated with a dynamic iteration methodology to get the increasing backlash generated by tooth accumulated wear for one pair of mating teeth under the condition that contact ratio equals to one. Then in order to introduce the tooth accumulated wear into dynamic model of compound planetary gear set, the backlash excitation generated by tooth accumulated wear for each meshing pair in compound planetary gear set is given under the condition that contact ratio equals to one and does not equal to one. Last, in order to investigate the impact of the increasing backlash generated by tooth accumulated wear on dynamic response of compound planetary gear set, a nonlinear lumped-parameter dynamic model of compound planetary gear set is employed to describe the dynamic relationships of gear transmission under the internal excitations generated by worn profile, meshing stiffness, transmission error, and backlash. The results indicate that the introduction of the increasing backlash generated by tooth accumulated wear makes a significant influence on the bifurcation and chaotic characteristics, dynamic response in time domain, and load sharing behavior of compound planetary gear set.

Investigation of nonlinear landing gear behavior and dynamic responses on high performance aircraft

2019 ◽  
Vol 233 (15) ◽  
pp. 5674-5688
Author(s):  
PS Suresh ◽  
Niranjan K Sura ◽  
K Shankar
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Landing Gear ◽  
Flight Mechanics ◽  
Dynamic Responses ◽  
Nonlinear Stiffness ◽  
Response Model ◽  
Nonlinear Dynamic Response ◽  
Vertical Descent ◽  
Stiffness And Damping

The dynamic responses simulation of aircraft as rigid body considering heave, pitch, and roll motions, coupled onto a tricycle landing gear arrangement is presented. Equation of motion for each landing gear consists of un-sprung mass vertical and longitudinal motions considering strut nonlinear stiffness and damping combined with strut bending flexibility. Initially, the nonlinear dynamic response model is subjected to an input of riding over staggered bump and the responses are compared with linear landing gear model. It is observed that aircraft dynamics and important landing gear events such as vertical, spin-up and spring-back are truly represented with nonlinear stiffness and damping model considering strut bending flexibility. Later, landing response analysis is performed, with the input from nonlinear flight mechanics model for several vertical descent rate cases. The aircraft and landing gear dynamic responses such as displacement, velocity, acceleration, and reaction forces are obtained. The vertical and longitudinal drag forces from the nonlinear dynamic response model is compared with “Book-case method” outlined in landing gear design technical specifications. From the reaction force ratio calculation, it is shown that for lower vertical descent rate case the predicted loads are lesser using nonlinear dynamic response model. The same model for higher vertical descent rate cases predicts higher ratios on vertical reaction for main landing gear and longitudinal reaction for nose landing gear, respectively. The scope for increase in fatigue life for low vertical descent rate landing covering major design spectrum and the concern for static strength and structural integrity consideration for higher vertical descent rate cases are discussed in the context of event monitoring on aircraft in services.

Numerical Modeling and Analysis of Nonlinear Dynamic Response for a Bolted Joint Beam Considering Interface Frictional Contact

2018 ◽  
Author(s):  
Dongwu Li ◽  
Chao Xu ◽  
Dong Wang ◽  
Lihua Wen
Keyword(s):  
Constitutive Model ◽  
Dynamic Response ◽  
Numerical Results ◽  
Experimental Results ◽  
Bolted Joints ◽  
Interface Element ◽  
Nonlinear Stiffness ◽  
Friction Contact ◽  
Structural Dynamic ◽  
Stiffness And Damping

For an assembled structure with many bolted joints, predicting its dynamic response with high fidelity is always a difficult problem, because of the nonlinearity introduced by friction contact between jointed interfaces. The friction contact results in nonlinear stiffness and damping to a structure. To realize predictive simulation in structural dynamic design, these nonlinear behaviors must be carefully considered. In this paper, the dynamics of a multi-bolt jointed beam is calculated. A modified IWAN constitutive model, which can consider both tangential micro/macro slip and nonzero residual stiffness at macroslip phase, is developed to model nonlinear contact behaviors due to joint interfaces. A whole interface element integrating the proposed constitutive model is developed. The element is used to model the nonlinear stiffness and damping caused by bolted joints. The interface element is placed between the two contact interfaces. The other part of the beam is modeled by linear beam elements. A Matlab code is developed to realize the proposed nonlinear finite element dynamic analysis method. A hammer impact experiment for the bolt-jointed beam is conducted under different excitation force levels. The calculated nonlinear numerical results are compared with experimental results. It is shown that the effect of joint nonlinearity on structural dynamics can be observed from the response predicted by the proposed method. The numerical results agree well with the experimental results. This work validates the necessary of using nonlinear joint model for dynamic simulation of jointed structures.

Study on Nonlinear Damping Properties of Hydro-Pneumatic Suspension System for XP302-Pneumatic Tyred Roller

2014 ◽  
Vol 945-949 ◽  
pp. 987-991
Author(s):  
Bang Sheng Xing ◽  
Ning Ning Wang ◽  
Le Xu
Keyword(s):  
Dynamic Performance ◽  
Nonlinear Damping ◽  
Suspension System ◽  
Nonlinear Stiffness ◽  
Damping Properties ◽  
Vehicle Dynamic ◽  
Nonlinear Mathematical Model ◽  
Computer Simulation Program ◽  
Pneumatic Suspension ◽  
Stiffness And Damping

The nonlinear stiffness and damping properties of the hydro-pneumatic suspension system are introduced, and the nonlinear mathematical model of it is established. Using MATLAB 2009b to establish the computer simulation program and draw out the nonlinear stiffness curve and damping properties curve of the hydro-pneumatic suspension system. Then, researching the influences of related parameters' changes on the nonlinear stiffness and damping properties of the hydro-pneumatic suspension system. The simulation of vehicle dynamic performance research's foundation is provided.

scholarly journals Influence of the "Ghost Reed" Simplification on the Bifurcation Diagram of a Saxophone Model

2019 ◽  
Vol 105 (6) ◽  
pp. 1291-1294 ◽  
Author(s):  
Tom Colinot ◽  
Louis Guillot ◽  
Christophe Vergez ◽  
Philippe Guillemain ◽  
Jean-Baptiste Doc ◽  
...  
Keyword(s):  
Bifurcation Diagram ◽  
Contact Force ◽  
Nonlinear Stiffness ◽  
Impact Model ◽  
Bifurcation Diagrams ◽  
Pressure Parameter ◽  
Stiffness And Damping ◽  
The Impact

This paper presents how the bifurcation diagram of a saxophone model is affected by the contact force limiting the displacement of the reed when it strikes the mouthpiece lay. The reed impact is modeled by a nonlinear stiffness and damping activated by contact with the lay. The impact model is compared with the "ghost reed" simplification, where the reed moves through the lay unimpeded. Bifurcation diagrams in both cases are compared, in terms of amplitude of the oscillations and location of the bifurcations, on the solution branches corresponding to the first and second register. The ghost reed simplification has limited influence at low values of the blowing pressure parameter: the diagrams are similar. This is true even for "beating reed" regimes, in which the reed coincides with the lay. The most noticeable discrepancies occur near the extinction of the oscillations, at high blowing pressure.

Effects of Impact on the Behavior of a Flexible Multiple Disk Clutch and Brake

1987 ◽  
Vol 109 (4) ◽  
pp. 416-421 ◽  
Author(s):  
Kosuke Nagaya
Keyword(s):  
Dynamic Response ◽  
Laplace Transform ◽  
Dynamic Behavior ◽  
Circular Plate ◽  
Static Load ◽  
Equation Of Motion ◽  
Dynamic Loads ◽  
The Laplace Transform ◽  
The Impact

This paper discusses the dynamic behavior of a flexible multiple disk clutch subjected to dynamic loads. The expressions for obtaining the dynamic response and the transmission torque of the clutch have been derived from the equation of motion of a circular plate by applying the Laplace transform procedure. The results for the clutch subjected to a static load have also been obtained. The comparison between both static and dynamic results has been made to clarify the effect of the impact of the load on the behavior of the clutch.

The Effects of Tire Properties and Their Interaction with the Ground and Suspension on Vehicle Dynamic Behavior — A Finite Element Approach

1999 ◽  
Vol 27 (4) ◽  
pp. 227-249 ◽  
Author(s):  
Y. Zhang ◽  
C. Hazard
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Practical Method ◽  
Suspension System ◽  
Vehicle Body ◽  
Vehicle Dynamic ◽  
Analysis Method ◽  
Element Analysis ◽  
Body Roll ◽  
The Impact

Abstract The effects of tire properties and their interaction with the ground and the suspension system on vehicle dynamic behavior was studied using a newly developed finite element analysis method. This analysis method used the explicit nonlinear dynamic code LS-DYNA as a solver and contained finite element models for both the vehicle body structure and subsystems like chassis/suspension. The case presented in this paper is curb impact. Different tire properties such as tire/wheel assembly mass, tire stiffness, tire inflation pressure, tire size, etc., as well as different curb heights, were used with the same vehicle body and suspension system. Simulation results of the impact forces, wheel center jumps, and vehicle body roll/pitch angles at impact are compared for different parameters of the tires and the curb. The analyses presented in this paper provided an accurate and practical method for tire and vehicle dynamics analysis.

Dynamic Response of Reticulated Domes under the Impact

2014 ◽  
Vol 638-640 ◽  
pp. 58-61
Author(s):  
Chang Wu ◽  
Xiu Li Wang ◽  
Ya Xiong Liang ◽  
Zhan Zhong Yin
Keyword(s):  
Dynamic Response ◽  
Failure Modes ◽  
Numerical Models ◽  
Single Layer ◽  
Response Mode ◽  
Object Size ◽  
Response Modes ◽  
Reticulated Domes ◽  
Parametric Analyses ◽  
The Impact

As the study of the dynamic response of single-layer reticulated domes under impact, Numerical models for single-layer Kiewitt-6 reticulated domes with sub steel cube column were established by the ANSYS/ LS-DYNA program and a dynamic analysis were carried out. Four failure modes for the reticulated domes were put forward according as the dynamic response and plastic deformation. The parametric analyses on the dynamic response of single-layer reticulated domes with sub steel cube column under the impact loading are carried out, by changing the impact velocity, mass of impact object, size of impact object and impact location.The effects of these parameters on the response mode of the structures are investigated, and the distribution regularity of the response modes of the structures with different parameters is explained.

Gyroscopic and Support Effects on the Steady-State Response of a Noncontacting Flexibly Mounted Rotor Mechanical Face Seal

1989 ◽  
Vol 111 (2) ◽  
pp. 200-206 ◽  
Author(s):  
I. Green
Keyword(s):  
Dynamic Response ◽  
Closed Form Solution ◽  
Form Solution ◽  
Steady State Response ◽  
Face Seal ◽  
State Response ◽  
High Speeds ◽  
Relative Response ◽  
Mechanical Face Seal ◽  
Stiffness And Damping

The dynamic behavior of a noncontacting rotary mechanical face seal is analyzed. A closed-form solution is presented for the response of a flexibly mounted rotor to forcing misalignments which normally exist due to manufacturing and assembly tolerances. The relative misalignment between the rotor and the stator, which is the most important seal parameter, has been found to be time dependent with a cyclically varying magnitude. The relative response is minimum when support stiffness and damping are minimum. The gyroscopic couple is shown to have a direct effect on the dynamic response. This effect is enhanced at high speeds, and depending on the ratio between the transverse and polar moments of inertia, it can either decrease or increase the dynamic response. Its effect is most beneficial to seal performance when the rotor is a “short disk.” A numerical example demonstrates that a flexibly-mounted rotor seal outperforms a flexibly mounted stator seal with regard to the total relative misalignment, the critical stator misalignment, and the critical speed.

scholarly journals The effect of high-frequency torsional impacts on the dynamic response of a drill string in a stick state

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401982857
Author(s):  
Liping Tang ◽  
Wei He ◽  
Xiaohua Zhu
Keyword(s):  
Dynamic Response ◽  
High Frequency ◽  
Impact Load ◽  
Drill String ◽  
Superposition Method ◽  
Drill Bit ◽  
Stick Slip ◽  
Mode Superposition Method ◽  
Study Results ◽  
The Impact

Stick–slip vibration is common in the oil well drilling process and is detrimental to down-hole equipment and drilling efficiency. In recent years, a new type of drilling technology, torsional impact drilling, has been developed to mitigate the stick–slip phenomena, particularly in the drilling of deep or abrasive formations. With this drilling technique, high-frequency torsional impacts are generated and applied to the drill bit, providing the drill bit with auxiliary energy. By mitigating or suppressing the stick–slip vibration, part of the energy wasted as a result of vibration can be regained. However, the effect of these impact loads on the dynamic response of a drill string in a stick state is unknown. In order to address this issue, a continuous system model of a drill string that includes torsional impact load was constructed. In the model, a Fourier series approach was used for the impact load, and the mechanical model was resolved with the mode superposition method. Case studies were done to understand the drill string dynamics, with and without the impact. The case study results demonstrate that high-frequency torsional impacts have little influence on the dynamic response of a drill string in a stick state.

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