Vibroacoustic design optimization of curved composite shells

2021 ◽  
Vol 29 (9_suppl) ◽  
pp. S1520-S1531
Author(s):  
Rilwan K Apalowo ◽  
Dimitrios Chronopoulos
Keyword(s):  
Optimal Design ◽  
Structural Design ◽  
Composite Structures ◽  
Sensitivity Analyses ◽  
Computational Time ◽  
Design Parameters ◽  
Sandwich Shell ◽  
Acoustic Transmission ◽  
Composite Shells ◽  
Model Composite

The need to simultaneously optimize the structural design properties, and attain a satisfactory vibroacoustic performance for composite structures, has been a challenging task for modern structural engineers. This work is aimed at developing a statistical energy analysis (SEA) based numerical scheme for computing the optimal design parameters of each individual layer of layered curved shells having arbitrary complexities and layering. The main novelty of the work focuses on the computation of SEA properties for curved composite shells and derive the sensitivities of the acoustic transmission coefficient, expressed through the computed SEA properties, with respect to the structural design characteristics to be optimized. A wave finite element approach is employed to calculate the wave propagation constants of the curved shell. The calculated wave constants are then applied to compute the vibroacoustic properties for the curved shell using a SEA approach. Sensitivity analyses are conducted on the vibroacoustic properties to estimate their response to changes in the structural properties. Gradient vector is then formulated and hence the Hessian matrix, which is employed to formulate a Newton-like optimisation algorithm for optimizing the properties of the layered composite shell. The developed scheme is applied to a sandwich shell; optimal design parameters of [Formula: see text] and [Formula: see text] are obtained for the facesheet and the core of the shell whose base parameters are [Formula: see text] and [Formula: see text], respectively. This simultaneously optimizes the structure with maximum stiffness and minimum mass and attains a satisfactory dynamic performance for acoustic transmission through the sandwich shell. The principal advantage of the scheme is the ability to accurately model composite panels of arbitrary curvature at a rational computational time.

scholarly journals Structural Design and Impact Analysis of Deployable Habitat Modules

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Yihong Hong ◽  
Wenjuan Yao ◽  
Yan Xu
Keyword(s):  
Structural Design ◽  
Impact Analysis ◽  
Dynamic Responses ◽  
Design Parameters ◽  
Composite Shells ◽  
Steel Cylinder ◽  
Low Speed ◽  
Fea Model ◽  
Future Space ◽  
Final Design

Space-deployable habitat modules provide artificial habitable environments for astronauts and will be widely used for the construction of future space stations and lunar habitats. A novel structural design concept of space-deployable habitat modules consisting of flexible composite shells and deployable trusses has been proposed. Geometric relationships of deployable trusses based on two types of scissor elements were formulated. Flexible composite shells of space habitat modules were designed, and a nonlinear FEA model using ANSYS software was described. Considering folding efficiencies, stiffness, and strength of the structures, the influences of design parameters were analyzed and the final design scheme of space-deployable habitat modules was determined. After detailing the structural designs, low-speed impact dynamic responses between the structures and a stainless steel cylinder were simulated. The analysis results show that dynamic responses are only significant at the point of low-speed impact. The works will provide technical supports for structural designs and engineering applications of space-deployable habitat modules.

Structural Design Optimization of Side/Rear Impact Guards Using a Coupled Genetic Algorithm Finite Element Method

2004 ◽  
Author(s):  
De-Shin Liu ◽  
Nan-Chun Lin ◽  
Chao-Chin Huang ◽  
Yin-Lee Meng
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Optimal Design ◽  
Computational Time ◽  
Design Parameters ◽  
Fe Model ◽  
Passenger Cars ◽  
Rear Impact ◽  
Structural Design Optimization ◽  
Energy Absorbing

Underride protective structure can reduce serious injures when passenger cars collide with the rear end or side of the heavy vehicle. This paper describes the use of Genetic Algorithm (GA) coupled with a dynamic, inelastic and large deformation finite element (FE) code LS-DYNA to search optimal design of the Side/Rear impact guards. In order to verify the accuracy of the FE model, the simulation results were compared with real experiments follow with the regulation ECE R73. The validated FE model then used to study the optimal design base on under running distance and total amount of energy absorbing capacity. The results from this study shown that this newly developed method not only can found multi-objective design parameters but also can reduce computational time significantly.

Vibration characteristics of steering columns with bellows

2001 ◽  
Vol 215 (2) ◽  
pp. 171-178
Author(s):  
K H Kim ◽  
G H Han ◽  
H K Kim
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Optimal Design ◽  
Vibration Characteristics ◽  
Sensitivity Analyses ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Negative Effects ◽  
Vibration Sensitivity ◽  
Element Method

Bellows can be used as collapse elements for automotive steering columns. The crash performance of the steering column can be significantly improved with the bellows. However, the bending flexibility of the bellows has negative effects on the vibration characteristics. An effort is made to improve the vibration characteristics of steering columns with bellows. To understand the effects of various design parameters on the collapse and vibration, sensitivity analyses are performed by the finite element method using Taguchi's scheme. It is shown that the structure of the upper mounting bracket is the most important parameter affecting the vibration characteristics. An optimal design is proposed for a lower tilt type steering column.

scholarly journals Linear optimal design of a magnetic repulsion negative stiffness structure

2021 ◽  
pp. 146134842199261
Author(s):  
Zhang Bao ◽  
Wang Xiaoping ◽  
Ge Xinfang
Keyword(s):  
Optimal Design ◽  
Structural Design ◽  
Simulation Analysis ◽  
Structural Parameters ◽  
Negative Stiffness ◽  
Design Parameters ◽  
Structural Parameter ◽  
Design Requirements

To reduce negative stiffness structure’s stiffness non-linearity, enhance its stability during entire working displacement range, and expand its allowable working displacement, the optimal design of negative stiffness structure based on magnetic repulsion is proposed, and its structural parameters are also provided. The new negative stiffness structure’s model is established to determine the structural design parameters. According to the change of the new negative stiffness structure’s stiffness curve, we select the structural parameter to meet the design requirements. In order to verify the effectiveness of the proposed negative stiffness structure, we carried out simulation analysis, and the results show that the optimized negative stiffness structure’s stiffness non-linearity is greatly reduced in a relatively longer displacement, and its stiffness stability is promoted substantially compared with the simple triple-magnet negative stiffness structure.

Three-dimensional modelling of auxetic sandwich panels for localised impact resistance

2015 ◽  
Vol 19 (3) ◽  
pp. 291-316 ◽  
Author(s):  
Gabriele Imbalzano ◽  
Phuong Tran ◽  
Tuan D Ngo ◽  
Peter VS Lee
Keyword(s):  
Plastic Deformation ◽  
Composite Structures ◽  
Impact Resistance ◽  
Three Dimensional ◽  
Sandwich Panels ◽  
Computational Time ◽  
Design Parameters ◽  
Similar Amount ◽  
Plastic Energy ◽  
Parametric Analyses

Sandwich panels with auxetic lattice cores confined between metallic facets are proposed for localised impact resistance applications. Their performance under localised impact is numerically studied, considering the rate-dependent effects. The behaviour of the composite structure material at high strain rates is modelled with the Johnson-Cook model. Parametric analyses are conducted to assess the performance of different designs of the hybrid composite structures. The results are compared with monolithic panels of equivalent areal mass and material in terms of deformations and plastic energy dissipation. Design parameters considered for the parametric analyses include the auxetic unit cell effective Poisson’s ratio, thickness of the facet, material properties and radius of the unit cell’s struts. Significant reduction in computational time is achieved by modelling a quarter of the panel, with shell elements for facets and beam elements for the auxetic core. With projectile impacts up to 200 m/s, the auxetic composite panels are found to be able to absorb a similar amount of energy through plastic deformation, while the maximum back facet displacements are reduced up to 56% due to localised densification and plastic deformation of the auxetic core.

Optimization and Modeling Composite Structures with PZT Layers

2013 ◽  
Vol 849 ◽  
pp. 108-114
Author(s):  
Piotr Kędziora
Keyword(s):  
Optimal Design ◽  
Composite Structures ◽  
Piezoelectric Materials ◽  
Piezoelectric Actuators ◽  
Optimal Placement ◽  
Present Formulation ◽  
Model Composite ◽  
Optimization Criteria ◽  
Laminated Structures

Piezoelectric materials are used as layers or fibers that are embedded within or bonded to the surfaces of a structure. The present formulation allows us to model composite structures behavior in all convenient manner for optimal design. In this paper, the various optimization criteria used for optimal placement of piezoelectric actuators on laminated structures are discussed.

Justification of design parameters of the fractional reaping conveyor and its devices for removal of beveled stems from under the wheels of the vehicle

2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych
Keyword(s):  
Optimal Design ◽  
Technological Process ◽  
Design Parameters ◽  
Theoretical Studies ◽  
Optimal Parameters ◽  
Belt Conveyor ◽  
Grain Crops ◽  
Mode Of Operation ◽  
Optimal Values ◽  
Main Component

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.

scholarly journals Optimal Design Parameters for a Phased Array Based Ultrasonic Polar Scan

2021 ◽  
pp. 1-1
Author(s):  
Jannes Daemen ◽  
Arvid Martens ◽  
Mathias Kersemans ◽  
Erik Verboven ◽  
Steven Delrue ◽  
...  
Keyword(s):  
Optimal Design ◽  
Phased Array ◽  
Design Parameters ◽  
Ultrasonic Polar Scan

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Sign in / Sign up

Export Citation Format

Share Document