Coating position optimization for a hard-coating thin-plate structure based on resonance response

2020 ◽  
pp. 1-15
Author(s):  
Wei Sun ◽  
Yue Sun ◽  
Rong Liu
Keyword(s):  
Thin Plate ◽  
Hard Coating ◽  
Superposition Method ◽  
Analysis Model ◽  
Optimal Position ◽  
Mode Superposition Method ◽  
Design Variables ◽  
Resonance Response ◽  
Design Requirements ◽  
Population Genetic Algorithm

The ultimate goal of vibration reduction using hard coating is to suppress the resonance peaks of the structure. Thus, the optimal position of the coating as a function of the resonance response will better satisfy the design requirements. Based on a full consideration of the continuous coating area, a method for optimizing the coating position with the objective of minimizing resonance response was developed for the hard-coating thin plate. A semi-analytical analysis model of the partially coated cantilever thin plate was created, and the formula for solving the vibration response was identified by the mode superposition method. An optimization model was established. In the model, the position coordinates of coating patches are the design variables, and the objective function is the maximizing of the reciprocals of the resonance peaks, which is equivalent to minimizing the resonance response. A multi-population genetic algorithm (MPGA) has been proposed to solve the coating position optimization problem. Finally, a cantilever titanium plate coated with NiCrAlCoY + YSZ hard coating was chosen to demonstrate the presented method. The results show that the obtained optimized results can guarantee that the resonance peaks of the hard-coating thin plate are always less than those of general cases, whether it is for single-order or multi-order optimization objectives.

Analysis on Vertical Dynamic Response of Simply-Supported Bridge Subjected to a Series of Moving Harmonic Loads

2013 ◽  
Vol 361-363 ◽  
pp. 1329-1334
Author(s):  
Jing Feng Zhang ◽  
Xiao Zhen Li ◽  
Li Zhong Song ◽  
Chun Sheng Shan
Keyword(s):  
Analytical Solution ◽  
Dynamic Response ◽  
Resonance Phenomenon ◽  
Superposition Method ◽  
Analysis Model ◽  
Harmonic Frequency ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Mode Superposition Method ◽  
Calculation Results

In this thesis, a dynamic analysis model is established that subjected to a series of moving harmonic loads, and the analytical solution of the dynamic response is deduced based on the mode superposition method. Based on this analytical solution, a program is made to calculate the vertical dynamic response of simply-supported beam. The calculation results show that the analytical solution is reasonable and correct. When the harmonic frequency is near to the fundamental frequency of the simply-supported beam, the resonance phenomenon will occur. The dynamic response of the beam will decrease as the speed increases, and the presence of damp can suppress the vibration of the bridge.

scholarly journals Concurrent Topology Optimization of Composite Plates for Minimum Dynamic Compliance

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 538
Author(s):  
Heng Zhang ◽  
Xiaohong Ding ◽  
Weiyu Ni ◽  
Yanyu Chen ◽  
Xiaopeng Zhang ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Frequency Response ◽  
Composite Plates ◽  
Dynamic Compliance ◽  
Superposition Method ◽  
Complex Frequency ◽  
Concurrent Topology Optimization ◽  
Periodic Composites ◽  
Mode Superposition Method ◽  
Design Variables

This paper proposes a novel density-based concurrent topology optimization method to support the two-scale design of composite plates for vibration mitigation. To have exceptional damping performance, dynamic compliance of the composite plate is taken as the objective function. The complex stiffness model is used to describe the material damping and accurately consider the variation of structural response due to the change of damping composite material configurations. The mode superposition method is used to calculate the complex frequency response of the composite plates to reduce the heavy computational burden caused by a large number of sample points in the frequency range during each iteration. Both microstructural configurations and macroscopic distribution are optimized in an integrated manner. At the microscale, the damping layer consists of periodic composites with distinct damping and stiffness. The effective properties of the periodic composites are homogenized and then are fed into the complex frequency response analysis at the macroscale. To implement the concurrent topology optimization at two different scales, the design variables are assigned for both macro- and micro-scales. The adjoint sensitivity analysis is presented to compute the derivatives of dynamic compliance of composite plates with respect to the micro and macro design variables. Several numerical examples with different excitation inputs and boundary conditions are presented to confirm the validity of the proposed methodologies. This paper represents a first step towards designing two-scale composite plates with optional dynamic performance under harmonic loading using an inverse design method.

Structure Sensitivity Analysis and Dynamic Performance Optimization of Marine Gearbox

2017 ◽  
Author(s):  
Tengjiao Lin ◽  
Daokun Xie ◽  
Ziran Tan ◽  
Bo Liu
Keyword(s):  
Sensitivity Analysis ◽  
Performance Optimization ◽  
Optimization Design ◽  
Dynamic Performance ◽  
Structure Sensitivity ◽  
Superposition Method ◽  
Structure Parameters ◽  
Analysis Model ◽  
Vibration Acceleration ◽  
Response Optimization

The aim of this paper is to investigate the influence of structure parameters on the vibration characteristics and improve the dynamic performance of marine gearbox. A finite element model was established to solve the dynamic response by using modal superposition method. Based on the theory of multi-objective optimization design, the structure sensitivity analysis model of marine gearbox was established, which takes the structure parameters of the housing as design variables. The modal and response sensitivity was obtained by using the optimal gradient method. According to the results of sensitivity analysis, a modal and response optimization model of marine gearbox was established. The objective was to avoid natural frequencies from the excitation frequencies and minimize the root mean square of vibration acceleration of the evaluating points on the surface of housing. Then the modal optimization and response optimization of gearbox were carried out by using zero-order and first-order optimization method. The results indicate that the dynamic optimization of the gearbox can be achieved. After optimization, the amplitude of vibration acceleration of the evaluating points on the housing surface has been reduced and the resonance of marine gearbox can be avoided.

scholarly journals Topology Optimization of Hard-Coating Thin Plate for Maximizing Modal Loss Factors

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Haitao Luo ◽  
Rong Chen ◽  
Siwei Guo ◽  
Jia Fu
Keyword(s):  
Topology Optimization ◽  
Objective Function ◽  
Composite Plates ◽  
Optimization Method ◽  
Hard Coating ◽  
Design Variables ◽  
Coating Composite ◽  
Damping Materials ◽  
Topology Optimization Method ◽  
Loss Factors

At present, hard coating structures are widely studied as a new passive damping method. Generally, the hard coating material is completely covered on the surface of the thin-walled structure, but the local coverage cannot only achieve better vibration reduction effect, but also save the material and processing costs. In this paper, a topology optimization method for hard coated composite plates is proposed to maximize the modal loss factors. The finite element dynamic model of hard coating composite plate is established. The topology optimization model is established with the energy ratio of hard coating layer to base layer as the objective function and the amount of damping material as the constraint condition. The sensitivity expression of the objective function to the design variables is derived, and the iteration of the design variables is realized by the Method of Moving Asymptote (MMA). Several numerical examples are provided to demonstrate that this method can obtain the optimal layout of damping materials for hard coating composite plates. The results show that the damping materials are mainly distributed in the area where the stored modal strain energy is large, which is consistent with the traditional design method. Finally, based on the numerical results, the experimental study of local hard coating composites plate is carried out. The results show that the topology optimization method can significantly reduce the frequency response amplitude while reducing the amount of damping materials, which shows the feasibility and effectiveness of the method.

Multiobjective optimization of hard coating parameters designing for damping of the bladed disk

2017 ◽  
Vol 232 (9) ◽  
pp. 1609-1619 ◽  
Author(s):  
Yugang Chen ◽  
Jingyu Zhai ◽  
Qingkai Han
Keyword(s):  
Pareto Front ◽  
Engineering Application ◽  
Front Surface ◽  
Model Material ◽  
Superior Performance ◽  
Hard Coating ◽  
Damping Capacity ◽  
Nsga Ii ◽  
Bladed Disk ◽  
Design Variables

In this paper, the damping capacity and the structural influence of the hard coating on the given bladed disk are optimized by the non-dominated sorting genetic algorithm (NSGA-II) coupled with the Kriging surrogate model. Material and geometric parameters of the hard coating are taken as the design variables, and the loss factors, frequency variations and weight gain are considered as the objective functions. Results of the bi-objective optimization are obtained as curved line of Pareto front, and results of the triple-objective optimization are obtained as Pareto front surface with an obvious frontier. The results can give guidance to the designer, which can help to achieve more superior performance of hard coating in engineering application.

scholarly journals Transient Response of Bridge Piers to Structure Separation under Near-Fault Vertical Earthquake

2021 ◽  
Vol 11 (9) ◽  
pp. 4068
Author(s):  
Wenjun An ◽  
Guquan Song
Keyword(s):  
Large Scale ◽  
Bending Moment ◽  
Relative Displacement ◽  
Superposition Method ◽  
Longitudinal Displacement ◽  
Transient Wave ◽  
Vibration Period ◽  
Vertical Excitation ◽  
Mode Superposition Method ◽  
Main Girder

Given the possible separation problem caused by the double-span continuous beam bridge under the action of the vertical earthquake, considering the wave effect, the transient wave characteristic function method and the indirect mode superposition method are used to solve the response theory of the bridge structure during the earthquake. Through the example analysis, the pier bending moment changes under different vertical excitation periods and excitation amplitudes are calculated. Calculations prove that: (1) When the seismic excitation period is close to the vertical natural vibration period of the bridge, the main girder and the bridge pier may be separated; (2) When the pier has a high height, the separation has a more significant impact on the longitudinal displacement of the bridge, but the maximum relative displacement caused by the separation is random; (3) Large-scale vertical excitation will increase the number of partitions of the structure, and at the same time increase the vertical collision force between the main girder and the pier, but the effect on the longitudinal displacement of the form is uncertain; (4) When V/H exceeds a specific value, the pier will not only be damaged by bending, but will also be damaged by axial compression.

scholarly journals Identification of Acoustic-Vibratory System by Acoustic Measurement

1996 ◽  
Vol 3 (1) ◽  
pp. 27-37
Author(s):  
Takuzo Iwatsubo ◽  
Shozo Kawamura ◽  
Masahito Kamada
Keyword(s):  
Inverse Analysis ◽  
Coefficient Matrix ◽  
Superposition Method ◽  
Vibration Modes ◽  
Identification Problems ◽  
Mathematical Property ◽  
Vibratory System ◽  
Stochastic Error ◽  
Mode Superposition Method ◽  
Ill Conditioning

A new method for reducing ill-conditioning in a class of identification problems is proposed. The key point of the method is that the identified vibration of the sound source is expressed as a superposition of vibration modes. The mathematical property of the coefficient matrix, the practical error expanding ratio, and the stochastic error expanding ratio are investigated in a numerical example. The mode-superposition method is shown to be an effective tool for acoustic-vibratory inverse analysis.

scholarly journals Dynamic Impact Factor Determination of an Existing Pre-stressed Concrete I-Girder Bridge Using Vehicle-Bridge Interaction Modelling

2021 ◽  
Vol 10 (3) ◽  
pp. 163-176
Author(s):  
Shuvrodeb Adhikary ◽  
Shohel Rana ◽  
Jerin Tasnim ◽  
Nazrul Islam
Keyword(s):  
Impact Factor ◽  
Dynamic Model ◽  
Superposition Method ◽  
Dynamic Impact ◽  
Mode Superposition Method ◽  
Road Roughness ◽  
Girder Bridge ◽  
Dynamic Impact Factor ◽  
Interaction Problem

The dynamic Impact Factor (IM) of a bridge is influenced by many factors, including Vehicle-Bridge Interaction (VBI), vehicle speed and road roughness. This paper represents the dynamic effects of moving vehicles and the determination of IM of an existing Pre-stressed concrete I-girder bridge utilizing VBI modeling. Evaluation of the IM is expected to provide valuable information for condition assessment and management of the existing bridge. The interaction problem between the vehicle and the bridge includes a dynamic model for the bridge structure subsystem, a dynamic model for the vehicle subsystem, interaction constraints, road roughness modelling and numerical solution techniques for the dynamic systems. The Half-car model is utilized for modelling of the vehicle dynamics and the bridge dynamic model is idealized according to Finite Element Method (FEM). Then FEM along with the mode superposition method are utilized for determining the Equation of Motion (EOM) for the bridge subsystem. D’Alembert’s principle is used for developing EOM for the vehicle subsystem. The interaction between vehicle vibration and bridge vibration is established through the contact forces between the wheels and the bridge by employing the compatibility relationship between the contact points and by applying the static equilibrium condition. Lastly, Newmark’s-β method is used for solving the coupled mathematical model of the vehicle and bridge interaction problem to determine the responses of the two sub-systems. The whole procedure is then performed for different vehicle speeds and various bridge deck surface roughness conditions to determine the dynamic impact on the existing I-girder bridge named Teesta Bridge located in Bangladesh.

Sign in / Sign up

Export Citation Format

Share Document