An Experimental Study of the Structural Dynamic Response of a Biomimetic Insect-Sized Wing

2017 ◽  
Author(s):  
Jose E. Rubio ◽  
Uttam K. Chakravarty
Keyword(s):  
Dynamic Response ◽  
Computer Aided Design ◽  
Insect Flight ◽  
Structural Response ◽  
Image Correlation ◽  
Micro Computed Tomography ◽  
Structural Dynamic ◽  
Venation Pattern ◽  
Plane Displacement ◽  
Artificial Wing

This investigation describes a method for both manufacturing a biomimetic insect-sized wing using the photolithography technique and experimentally analyzing its structural dynamic response. The wing geometry of a crane fly forewing is captured using a micro-computed tomography scanner for its replication. A photomask of the membrane and venation pattern is designed from a computer-aided design model developed from the reconstructed scanned model of the wing. The photolithography process is conducted using the negative photoresist SU-8 and the Kapton film to biomimic the veins and the membrane of the crane fly forewing, respectively. A digital image correlation (DIC) system is used in conjunction to a shaker vibrational setup to determine the natural frequencies of the artificial wing from the fast Fourier transform of the time-varying out-of-plane displacement data. Wind-tunnel experiments are conducted using the DIC system to determine the structural response of the artificial wing under different freestream velocities and angles of attack within the regime of insect flight. The vibration modes are dominated by a bending and torsional deformation response. The deformation along the span of the wing increases nonlinearly from the root to the tip of the wing with Reynolds number.

scholarly journals Integrating a Hive Triangle Pattern with Subpixel Analysis for Noncontact Measurement of Structural Dynamic Response by Using a Novel Image Processing Scheme

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yung-Chi Lu ◽  
Shih-Lin Hung ◽  
Tzu-Hsuan Lin
Keyword(s):  
Image Processing ◽  
Digital Image Correlation ◽  
Dynamic Response ◽  
Digital Image ◽  
Time History ◽  
Image Correlation ◽  
Estimation Accuracy ◽  
Structural Dynamic ◽  
Processing Scheme ◽  
Noncontact Measurement

This work presents a digital image processing approach with a unique hive triangle pattern by integrating subpixel analysis for noncontact measurement of structural dynamic response data. Feasibility of proposed approach is demonstrated based on numerical simulation of a photography experiment. According to those results, the measured time-history displacement of simulated image correlates well with the numerical solution. A small three-story frame is then mounted on a small shaker table, and a linear variation differential transformation (LVDT) is set on the second floor. Experimental results indicate that the relative error between data from LVDT and analyzed data from digital image correlation is below 0.007%, 0.0205 in terms of frequency and displacement, respectively. Additionally, the appropriate image block affects the estimation accuracy of the measurement system. Importantly, the proposed approach for evaluating pattern center and size is highly promising for use in assigning the adaptive block for a digital image correlation method.

Discussion on Safety Criterion of Structural Response to Blasting Vibration

2011 ◽  
Vol 138-139 ◽  
pp. 134-139
Author(s):  
Hai Xia Wei ◽  
Ting Liu ◽  
Jie Zhu ◽  
Li Jian Tan
Keyword(s):  
Dynamic Response ◽  
Structural Characteristics ◽  
Wavelet Packet ◽  
Structural Response ◽  
Blasting Vibration ◽  
Safety Criterion ◽  
Structural Dynamic ◽  
Single Degree ◽  
Vibration Loads

Taking a structure of single-degree freedom as analyzed object, the problem of structural dynamic response to blasting vibration loads was transformed into the problem of that to a series of simple harmonic loads with wavelet packet method. A safety criterion of structural response to blasting vibration has been put forward, which is more detailed, reasonable and scientific than others in use with involving parameters related to structural characteristics, blasting energy, blasting amplitude, blasting frequency and blasting duration.

scholarly journals Simplification of Complex Structural Dynamic Models: A Case Study Related to a Cantilever Beam and a Large Mass Attachment

2021 ◽  
Vol 11 (12) ◽  
pp. 5428
Author(s):  
Patrick Langer ◽  
Christopher Jelich ◽  
Christian Guist ◽  
Andrew Peplow ◽  
Steffen Marburg
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Dynamic Response ◽  
Boundary Conditions ◽  
Computer Aided Design ◽  
Large Scale ◽  
Dynamic Models ◽  
Large Mass ◽  
Structural Dynamic ◽  
Industrial Sectors

Large attachments can dramatically affect the dynamic response of an assembled structure. In various industrial sectors, e.g., the automotive, aircraft, and shipbuilding industries, it is often necessary to predict the dynamic response of assembled structures and large attachments in early-stage engineering design. To deal with this, it is often the finite element method (FEM) that is used in the vibrational analysis. Despite the advent of large-scale computer availability, it is still commonplace, and often necessary, to reduce the model-size with large attachments to acceptable levels for computer time-scale or memory-size limitations. This article discusses the simple methodology of replacing large and sometimes complicated attachments by using a simplified boundary condition. This methodology is well-known in certain sectors of computer-aided design, but here we are able to present a comprehensive discussion from laboratory measurements, finite element analysis and a simplified perspective. Given the availability of experimental data, the errors produced by these methodologies may then be determined by a structure that has a strictly defined geometry and known material properties within a certain tolerance. To demonstrate these effects, an experimental modal analysis is performed on a structure consisting of a beam and a large mass attachment, which is then validated by each of the finite element models that include the relevant approximate ideal boundary conditions. Various approximating boundary conditions are investigated, and quantifiable results are discussed. One of the conclusions confirms the recommendation that rotary inertia terms should be included as a boundary condition wherever possible when large attachments are approximated by an offset mass defined at a point.

Research on the Effect of Fluid-Structure Interaction on Dynamic Response of Gate Structure

2011 ◽  
Vol 199-200 ◽  
pp. 811-818
Author(s):  
Hua Gu ◽  
Gen Hua Yan
Keyword(s):  
Dynamic Response ◽  
Interaction Effect ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Response Characteristics ◽  
Gate Structure ◽  
The Impact

This essay reveals that on the basis of fluid-structure interaction having appreciable impact on auto-vibration of gate structure, analysis and calculation on dynamic response characteristics of gate structural fluid-structure interaction have been conducted. The results indicate that under the same dynamic load the structural dynamic response value with fluid-structure interaction effect considered is remarkably larger than vibration response with fluid-structure interaction effect considering. The calculating results indicate that the largest response increase of typical parts of gate structure is from 50% to 60%. Therefore, as to making calculations on structural dynamic response with fluid-structure interaction effect, the impact flow field exerting on structural response should be taken into consideration.

Probabilistic analyses of structural dynamic response with modified Kriging-based moving extremum framework

2021 ◽  
Vol 125 ◽  
pp. 105398
Author(s):  
Cheng Lu ◽  
Cheng-Wei Fei ◽  
Yun-Wen Feng ◽  
Yong-Jun Zhao ◽  
Xiao-Wei Dong ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Structural Dynamic

scholarly journals Sensor Integrated Load-Bearing Structures: Measuring Axis Extension with DIC-Based Transducers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4104
Author(s):  
Nassr Al-Baradoni ◽  
Peter Groche
Keyword(s):  
Cost Effective ◽  
Image Correlation ◽  
Maximum Deviation ◽  
Single Image ◽  
Eccentric Load ◽  
Load Bearing ◽  
Out Of Plane ◽  
Axis Extension ◽  
Plane Displacement ◽  
Imaging Sensor

In this paper we present a novel, cost-effective camera-based multi-axis force/torque sensor concept for integration into metallic load-bearing structures. A two-part pattern consisting of a directly incident and mirrored light beam is projected onto the imaging sensor surface. This allows the capturing of 3D displacements, occurring due to structure deformation under load in a single image. The displacement of defined features in size and position can be accurately analyzed and determined through digital image correlation (DIC). Validation on a prototype shows good accuracy of the measurement and a unique identification of all in- and out-of-plane displacement components under multiaxial load. Measurements show a maximum deviation related to the maximum measured values between 2.5% and 4.8% for uniaxial loads ( and between 2.5% and 10.43% for combined bending, torsion and axial load. In the course of the investigations, the measurement inaccuracy was partly attributed to the joint used between the sensor parts and the structure as well as to eccentric load.

scholarly journals Characterization and ballistic performance of thin pre-damaged resin-starved aramid-fiber composite panels

2021 ◽  
pp. 004051752110134
Author(s):  
Cerise A Edwards ◽  
Stephen L Ogin ◽  
David A Jesson ◽  
Matthew Oldfield ◽  
Rebecca L Livesey ◽  
...  
Keyword(s):  
Fiber Composite ◽  
Plane Deformation ◽  
Ballistic Impact ◽  
Image Correlation ◽  
Composite Panel ◽  
Composite Panels ◽  
Micro Computed Tomography ◽  
Ballistic Performance ◽  
Low Level ◽  
Out Of Plane

Military personnel use protective armor systems that are frequently exposed to low-level damage, such as non-ballistic impact, wear-and-tear from everyday use, and damage during storage of equipment. The extent to which such low-level pre-damage could affect the performance of an armor system is unknown. In this work, low-level pre-damage has been introduced into a Kevlar/phenolic resin-starved composite panel using tensile loading. The tensile stress–strain behavior of this eight-layer material has been investigated and has been found to have two distinct regions; these have been understood in terms of the microstructure and damage within the composite panels investigated using micro-computed tomography and digital image correlation. Ballistic testing carried out on pristine (control) and pre-damaged panels did not indicate any difference in the V50 ballistic performance. However, an indication of a difference in response to ballistic impact was observed; the area of maximal local out-of-plane deformation for the pre-damaged panels was found to be twice that of the control panels, and the global out-of-plane deformation across the panel was also larger.

Theoretical and Numerical Analysis on the Seismic Response of Underground Structures in Existence of Isolators

2011 ◽  
Vol 368-373 ◽  
pp. 710-714
Author(s):  
Jin Chun Liu ◽  
Yi Huan
Keyword(s):  
Dynamic Response ◽  
Analytical Procedure ◽  
Axial Loading ◽  
Seismic Loading ◽  
Underground Structures ◽  
Structural Dynamic ◽  
Metro Station ◽  
Single Degree Of Freedom ◽  
Theoretical And Numerical Analysis ◽  
Elastically Supported

In this paper, an analytical method of the beam with springs and dampers fixed at the ends was proposed based on equivalent single degree of freedom (SDOF) system and secondary Lagrange’s dynamic equations, in order to develop a new effective method to enhance the aseismic capability of underground structures. The dynamic response of elastically supported and damply supported beams subjected to both seismic loading and static axial loading was analyzed by the proposed analytical procedure. The theoretical results were validated by the numerical simulation. In order to further investigate the effects of springs and dampers fixed at the ends of the columns in nonlinear response situation, the 3D nonlinear seismic responses of the Dakai metro station structure with and without the isolators were analyzed by ABAQUS respectively. It is demonstrated that: (1) the proposed analytical procedure can predict the dynamic response of beams with elastic and damper supports subjected to both seismic loading and axial loading. (2) Setting isolators at the supports of the column could enhance the aseismic capability of the structure effectively. (3) The axial static loading induced by the gravity of the soil and structure provide the constraint on the column, and therefore could not be neglected in the structural dynamic analysis.

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