scholarly journals Towards locust-inspired gliding wing prototypes for micro aerial vehicle applications

2021 ◽  
Vol 8 (6) ◽  
pp. 202253
Author(s):  
Hamid Isakhani ◽  
Caihua Xiong ◽  
Wenbin Chen ◽  
Shigang Yue
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Element Analysis ◽  
Micro Aerial Vehicle ◽  
Maximum Deformation ◽  
Insect Wings ◽  
Wing Structures ◽  
Aerial Vehicle ◽  
Manufacturing Methods ◽  
Locust Wing

In aviation, gliding is the most economical mode of flight explicitly appreciated by natural fliers. They achieve it by high-performance wing structures evolved over millions of years in nature. Among other prehistoric beings, locust is a perfect example of such natural glider capable of endured transatlantic flights that could inspire a practical solution to achieve similar capabilities on micro aerial vehicles. An investigation in this study demonstrates the effects of haemolymph on the flexibility of several flying insect wings proving that many species exist with further simplistic yet well-designed wing structures. However, biomimicry of such aerodynamic and structural properties is hindered by the limitations of modern as well as conventional fabrication technologies in terms of availability and precision, respectively. Therefore, here we adopt finite-element analysis to investigate the manufacturing-worthiness of a three-dimensional digitally reconstructed locust wing, and propose novel combinations of economical and readily available manufacturing methods to develop the model into prototypes that are structurally similar to their counterparts in nature while maintaining the optimum gliding ratio previously obtained in the aerodynamic simulations. The former is assessed here via an experimental analysis of the flexural stiffness and maximum deformation rate as EI s = 1.34 × 10 −4 Nm 2 , EI c = 5.67 × 10 −6 Nm 2 and greater than 148.2%, respectively. Ultimately, a comparative study of the mechanical properties reveals the feasibility of each prototype for gliding micro aerial vehicle applications.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

2009 ◽  
Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Element Analysis ◽  
Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

Three-Dimensional Obstacle Avoidance of Blimp-Type Unmanned Aerial Vehicle Flying in Unknown and Non-Uniform Wind Disturbance

2007 ◽  
Vol 19 (2) ◽  
pp. 166-173 ◽  
Author(s):  
Hiroshi Kawano ◽  
Keyword(s):  
Motion Planning ◽  
Obstacle Avoidance ◽  
Unmanned Aerial Vehicle ◽  
High Performance ◽  
Three Dimensional ◽  
Longitudinal Motion ◽  
Wind Disturbance ◽  
Flow Disturbances ◽  
Markov Decision ◽  
Aerial Vehicle

A blimp-type unmanned aerial vehicle (BUAV) maintains its longitudinal motion using buoyancy provided by the air around it. This means the density of a BUAV equals that of the surrounding air. Because of this, the motion of a BUAV is seriously affected by flow disturbances, whose distribution is usually non-uniform and unknown. In addition, the inertia in the heading motion is very large. There is also a strict limitation on the weight of equipment in a BUAV, so most BUAVs are so-called under-actuated robots. From this situation, it can be said that the motion planning of the BUAV considering the stochastic property of the disturbance is needed for obstacle avoidance. In this paper, we propose an approach to the motion planning of a BUAV via the application of Markov decision process (MDP). The proposed approach consists of a method to prepare a discrete MDP model of the BUAV motion and a method to maintain the effect of the unknown wind on the BUAV’s motion. A dynamical simulation of a BUAV in an environment with wind disturbance shows high performance of the proposed method.

Finite Element Analysis on Hybrid City Bus Frame Based on ANSYS-Workbench14

2014 ◽  
Vol 662 ◽  
pp. 214-219 ◽  
Author(s):  
Ming Lei Wan ◽  
Zuo Qiang Dai ◽  
Hong Xin Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Analysis ◽  
Maximum Deformation ◽  
City Bus ◽  
Three Dimensional Modeling ◽  
New Energy ◽  
Inherent Frequency ◽  
Stress And Deformation

Abstract. For analyzing the frame whether meets actual driving needs, LCK6105PHENV-type hybrid (electric and gas) city bus frame as research object, using Solidworks12 and ANSYS-Workbench14 on frame, respectively, for the three-dimensional modeling and finite element analysis. Static analysis obtains frame’s stress and deformation results under the condition of bending and reversing (wheels dangling), modal analysis gets frame’s front 6 order vibration type, inherent frequency and the maximum deformation. Analyzing results shows that the frame basically can meet the design requirements, and in line with the actual needs of living and production. This research will provide references for optimization and improvement of new-energy Auto frame.

Three-Dimensional Creep Analysis of Solder Joints in Surface Mount Devices

1995 ◽  
Vol 117 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Pardeep K. Bhatti ◽  
Klaus Gschwend ◽  
Abel Y. Kwang ◽  
Ahmer R. Syed
Keyword(s):  
High Performance ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Nonlinear Material ◽  
Computational Time ◽  
Nonlinear Creep ◽  
Element Analysis ◽  
Surface Mount ◽  
Creep Analysis ◽  
Highly Nonlinear

Three-dimensional finite element analysis has been applied for determining time-dependent solder joint response of leaded surface mount components under thermal cycling. Two main challenges are the geometric complexity in mesh development and computationally intensive analysis because of the highly nonlinear material properties. Advanced techniques have been applied, including multi-point constraints for mesh transition, which reduces the number of degrees of freedom in the model, and substructuring, which effectively reduces computational time in the iterative analysis. The result is a generic approach for nonlinear creep analysis using commercial FEA software on a high performance workstation. Illustrations are provided for J and gullwing leaded packages.

scholarly journals Finite element analysis of occlusal splint therapy in patients with bruxism

2019 ◽  
Author(s):  
Seifollah Gholampour ◽  
Hanie Gholampour ◽  
Hamed Khanmohammadi
Keyword(s):  
Maximum Stress ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Occlusal Splint ◽  
Element Analysis ◽  
Jaw Bone ◽  
Maximum Deformation ◽  
Splint Therapy ◽  
Control Subjects

Abstract Background: Bruxism is among the habits considered generally as contributory factors for temporomandibular joint (TMJ) disorders and its etiology is still controversial.Methods: Three-dimensional models of maxilla and mandible and teeth of 37 patients and 36 control subjects were created using in-vivo image data. The maximum values of stress and deformation were calculated in 21 patients six months after using a splint and compared with those in the initial conditions. Results: The maximum stresses in the jaw bone and head of mandible were respectively 4.4 and 4.1 times higher in patients than in control subjects. Similar values for deformation were 5.8 and 4.9, respectively. The maximum stress in the jaw bone and head of mandible decreased six months after splint application by up to 71.0% and 72.8%, respectively. Similar values for the maximum deformation were 80.7% and 78.7%, respectively. Following the occlusal splint therapy, the approximation of maximum deformation to the relevant values in control subjects was about 2.6 times the approximation of maximum stress to the relevant values in control subjects. The maximum stress and maximum deformation occurred in all cases in the head of the mandible and the splint had the highest effectiveness in jaw bone adjacent to the molar teeth. Conclusions: Splint acts as a stress relaxer and dissipates the extra stresses generated as well as the TMJ deformation and deviations due to bruxism. The splint also makes the bilateral and simultaneous loading possible and helps with the treatment of this disorder through regulation of bruxism by creating a biomechanical equilibrium between the physiological loading and the generated stress.

Finite Element Analysis on Dynamic Characteristics of Maglev Suspension System

2013 ◽  
Vol 834-836 ◽  
pp. 1497-1500
Author(s):  
Jian Xiang Tang ◽  
Xin Hua Jiang ◽  
Jiang Min Deng ◽  
Te Fang Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Characteristics ◽  
High Performance ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Suspension System ◽  
Three Dimensional Model ◽  
Maglev Train ◽  
Element Analysis

In this paper, electromagnetic dynamic characteristics of suspension system of middle-low speed maglev train are analyzed with finite element analysis (FEA) method based on the high-performance computing platform (HPC). The couple structure between F-type track and suspension magnet is meshed by pretension element. The dynamic characteristics of suspension system are simulated in three-dimensional model with 4 degrees of freedom motions condition. Both the numerical simulations and the actual force tests of suspension system are carried out with the same input. The result shows that the calculation accuracy of finite element analysis is high.

scholarly journals The Zurich urban micro aerial vehicle dataset

2017 ◽  
Vol 36 (3) ◽  
pp. 269-273 ◽  
Author(s):  
András L Majdik ◽  
Charles Till ◽  
Davide Scaramuzza
Keyword(s):  
Three Dimensional ◽  
Ground Truth ◽  
Ground Level ◽  
Urban Environments ◽  
Sensor Data ◽  
Measurement Unit ◽  
Reconstruction Algorithms ◽  
Ground Truth Data ◽  
Micro Aerial Vehicle ◽  
Aerial Vehicle

This paper presents a dataset recorded on-board a camera-equipped micro aerial vehicle flying within the urban streets of Zurich, Switzerland, at low altitudes (i.e. 5–15 m above the ground). The 2 km dataset consists of time synchronized aerial high-resolution images, global position system and inertial measurement unit sensor data, ground-level street view images, and ground truth data. The dataset is ideal to evaluate and benchmark appearance-based localization, monocular visual odometry, simultaneous localization and mapping, and online three-dimensional reconstruction algorithms for micro aerial vehicles in urban environments.

Experimental investigation on lift generation of flapping MAV with insect wings of various species

2019 ◽  
Vol 92 (2) ◽  
pp. 139-144
Author(s):  
Syam Narayanan S. ◽  
Asad Ahmed R. ◽  
Jijo Philip Varghese ◽  
Gopinath S. ◽  
Jedidiah Paulraj ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Design Methodology ◽  
Span Length ◽  
Micro Aerial Vehicle ◽  
Content Type ◽  
Insect Wing ◽  
Insect Wings ◽  
Aerial Vehicle ◽  
The Military ◽  
Practical Implications

Purpose The purpose of this paper is to experimentally analyze the effect of wing shape of various insects of different species in a flapping micro aerial vehicle (MAV). Design/methodology/approach Six different wings are fabricated for the MAV configuration, which is restricted to the size of 15 cm length and width; all wings have different surface area and constant span length of 6 cm. The force is being measured with the help of a force-sensing resistor (FSR), and the coefficients of lift were calculated and compared. Findings This study shows that the wing “Tipula sp” has better value of lift than other insect wings, except for the negative angle of attacks. The wing “Aeshna multicolor” gives the better values of lift in negative angles of attack. Practical implications This paper lays the foundation for the development of flapping MAVs with the insect wings. This type of wing can be used for spying purpose in the military zone and also can be used to survey remote and dangerous places where humans cannot enter. Originality/value This paper covers all basic insect wing configurations of different species with exact mimics of the veins. As the experimental investigation was carried for different angle of attacks, velocities and flapping frequencies, this paper can be used as reference for future flapping wing MAV developers.

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