Design and analysis of a propulsion mechanism using modular umbrella-like wings

2018 ◽  
Vol 122 (1249) ◽  
pp. 349-368
Author(s):  
F. Gao ◽  
J. G. Lv ◽  
X. C. Zhang
Keyword(s):  
Structural Model ◽  
Aerodynamic Force ◽  
Inertial Force ◽  
Structure Design ◽  
Symmetrical Structure ◽  
Propulsion Mechanism ◽  
New Type ◽  
Practical Guidance ◽  
Mechanical Performances ◽  
Relationship Of

ABSTRACTThis article describes the design and evaluation of a new type of propulsion mechanism that uses modular umbrella-like wings oscillating symmetrically in counterphase to generate thrust. The principle of the propulsion and movement of the modular umbrella-like wings was first developed, and the mechanism used to implement the movement of the modular wings was subsequently designed. A structural model and the assembly relationship of the propulsion mechanism were developed for prototype fabrication. An experiment was established to measure the kinematic and mechanical performances of the propulsion mechanism for different reciprocating frequencies and travels. The results for the single umbrella-like wing indicate that either increasing the frequency or enlarging the travel can enhance the average aerodynamic force generated by the wing in one cycle. The results for the modular umbrella-like wings demonstrate that the inertial force generated by the mechanism can be balanced using a symmetrical structure. The average aerodynamic force would be markedly enhanced by increasing the percentage of the time that the outspread wing is moving downwards; e.g. the average aerodynamic force generated by the modular umbrella-like wings was increased by 85.84% compared to the value for a single umbrella-like wing for the same travel and frequency. This work provides practical guidance for optimising the structure design.

scholarly journals Model Analysis and Optimization of BIM Technology in High-rise Shear Wall Residential Structure

2019 ◽  
Vol 267 ◽  
pp. 02001
Author(s):  
Liangli Xiao ◽  
Yan Liu ◽  
Zhuang Du ◽  
Zhao Yang ◽  
Kai Xu
Keyword(s):  
Structural Analysis ◽  
Collaborative Design ◽  
Structural Model ◽  
Structural Information ◽  
Shear Wall ◽  
Structure Design ◽  
Secondary Development ◽  
Optimized Design ◽  
Analysis Model ◽  
High Rise

This study combines specific high-rise shear wall residential projects with the Revit to demonstrate BIM application processes. The use of R-Star CAD may help to realize the link barrier of the building information model and the structural analysis software PKPM. Sequentially, the information supplement of the structural analysis model is completed by extracting the structural information with the Revit secondary development. By the collaborative design platform based on BIM technology, the paper examines the collision check of structural model, conducts collision analysis on other professional models and modifies the design scheme for conflict points. After the statistics of material usage, an optimized design is proposed. The findings of this paper could contribute to provide some reference for the specific application of BIM in structural design and realize the application of BIM technology in the process of building structure design.

scholarly journals Loading Performance of a Novel Shearer Drum Applied to Thin Coal Seams

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 358
Author(s):  
Kuidong Gao ◽  
Xiaodi Zhang ◽  
Liqing Sun ◽  
Qingliang Zeng ◽  
Zhihai Liu
Keyword(s):  
Rotational Speed ◽  
Production Efficiency ◽  
Loading Rate ◽  
Positive Impact ◽  
Structural Parameters ◽  
Helix Angle ◽  
Structure Design ◽  
Coal Seams ◽  
Coal Particles ◽  
Relationship Of

The poor loading performance of shearer drums restricts the development and production efficiency of coal in thin coal seams. Changing operation and structural parameters can improve the drum’s loading performance to some extent, but the effect is not obvious. A two-segment differential rotational speed drum (TDRSD) was proposed after analyzing the drum’s influence mechanism on coal particles. To further reveal the drum’s coal loading principle, the velocity, particles distribution, and loading rate were analyzed. The effect of the matching relationship of the rotational speed and helix angle between the front and rear drum are also discussed. The results show that a lower front drum rotational speed had a positive impact on improving the loading performance, and the loading rate first increases and then decreases with the increase in rear drum rotational speed. The optimal loading performance was obtained in the range 60–67.5 rpm. The front drum’s helix angle had no evident effect on loading performance, and the loading rate increase with the increase in the rear drum’s helix angle. The results provide a reference and guidance for operation parameters selection, structure design, and drum optimization.

Kinematic characteristics of longitudinal double folding wings

2021 ◽  
pp. 1-25
Author(s):  
L. Tiegang ◽  
C. Guoguang ◽  
L. Shuai
Keyword(s):  
Angular Velocity ◽  
Structural Model ◽  
Initial Conditions ◽  
Aerodynamic Force ◽  
Model Simulation ◽  
Lagrange Equation ◽  
Grid Method ◽  
Weapon Systems ◽  
Folding Wing ◽  
Double Folding

ABSTRACT A folding wing is a tactical missile launching device that needs to be miniaturised to facilitate storage, transportation, and launching; save missile and transportation space; and improve the combat capability of weapon systems. This study investigates the aeroelastic characteristics of the secondary longitudinal folding wing during the unfolding process. First, the Lagrange equation is used to establish the structural dynamics model of the folding wing, the kinematics characteristics during the deformation process are analysed, and the unfolding movement of the folding wing is obtained using the dynamic equations in the process. Then, the generalised unsteady aerodynamic force is calculated using the dipole grid method, and the multi-body dynamics equation of the folding wing is obtained. The initial angular velocity required for the deployment of the folding wing is analysed through structural model simulation, and the influence of the initial angular velocity on the opening process is studied. Finally, aeroelastic flutter analysis is performed on the folding wing, and the physical model of the folding wing verified experimentally. Results show that the type of aeroelastic response is sensitive to the initial conditions and the way the folding wing opens.

The Research and Simulation Analysis of a New Type of Translational Transmission Device

2014 ◽  
Vol 556-562 ◽  
pp. 1408-1412
Author(s):  
Zhi Qiang Zhang
Keyword(s):  
Modeling And Simulation ◽  
Theoretical Foundation ◽  
Simulation Analysis ◽  
Structural Modeling ◽  
Structural Features ◽  
Practical Application ◽  
Optimization Analysis ◽  
New Type ◽  
Mechanism Parameter ◽  
Relationship Of

In this paper, the following work is done: a new type of translational transmission device is designed; explained in detail are the operating principle, structural features, relationship of mechanism parameter and non interference conditions of the movement; the optimization analysis of transmission device is implemented on the basis of non interference conditions of the bucket movement; structural modeling and simulation analysis are carried out by utilization of Pro/e & Recurdyn; and based on virtual prototype technology, the new type of translational transmission device is verified by experiments, the data of which prove the translational transmission device reasonable and practicable. In conclusion, this paper has laid the theoretical foundation of the practical application of the translational transmission device.

Dynamic Characteristics Analysis of Cable-Rib Tension Deployable Antenna

2016 ◽  
Author(s):  
Liu Ruiwei ◽  
Hongwei Guo ◽  
Zhang Qinghua ◽  
Rongqiang Liu ◽  
Tang Dewei
Keyword(s):  
Dynamic Characteristics ◽  
Structural Parameters ◽  
Element Model ◽  
Structure Design ◽  
Antenna Structure ◽  
Characteristics Analysis ◽  
New Type ◽  
Dynamic Characteristics Analysis ◽  
The Finite Element Model ◽  
Weight Dynamic

Balancing stiffness and weight is of substantial importance for antenna structure design. Conventional fold-rib antennas need sufficient weight to meet stiffness requirements. To address this issue, this paper proposes a new type of cable-rib tension deployable antenna that consists of six radial rib deployment mechanisms, numerous tensioned cables, and a mesh reflective surface. The primary innovation of this study is the application of numerous tensioned cables instead of metal materials to enhance the stiffness of the entire antenna while ensuring relatively less weight. Dynamic characteristics were analyzed to optimize the weight and stiffness of the antenna with the finite element model by subspace method. The first six orders of natural frequencies and corresponding vibration modes of the antenna structure are obtained. In addition, the effects of structural parameters on natural frequency are studied, and a method to improve the rigidity of the deployable antenna structure is proposed.

Lateral Thinking and Learning in Arts Education in the Post-Internet Art

2021 ◽  
Author(s):  
Lynda Avendaño Santana
Keyword(s):  
New Technologies ◽  
Virtual Space ◽  
Self Awareness ◽  
Social Nature ◽  
The Arts ◽  
Internet Art ◽  
Creative Experience ◽  
New Type ◽  
Lateral Thinking ◽  
Relationship Of

Lateral learning in the last two decades can be seen in peer-to-peer learning that is being promoted by new technologies where there are apps that allow students to work together in real time through virtual space, a method which thereby shifts the focus from the solitary self to the interdependent group which lives an educational experience of a collaborative and distributed nature, whose focus lies in instilling the principle of the social nature of knowledge. The ideological bases of lateral thinking are sustained by issues such as emancipation of the student from the authority of the teacher, the relationship of collaboration, permitting the development of individual appreciations and ideas, based simultaneously on those of their peers, on the democratization of knowledge, and so on, which ultimately refers to a collaborative creative education, to a democratic education, and to an education for democracy that assumes the new technologized context in which we live. Because of this, lateral thinking is increasingly influencing everyday life and areas such as education and the arts, as it happens in the post-Internet art, and more specifically net.art (i.e., an online art), which is a collaborative creative experience that has become an instrument which allows us to see a “new type of art in the 21st century.” Net.art, Internet art and the most experimental design, therefore constitutes a community experience that hypertextualizes computerized languages and generates poetic perspectives as artistic practices of lateral thinking. It has bestowed upon us a series of mechanisms to devise collaborative development strategies for lateral learning based on those creative ludic educational experiences of using and interacting with new technologies. This is essential to bear in mind because, as Jeremy Rifkin says, collaborative learning helps students to expand their own self-awareness, including their “self” in reference to diverse “others,” and promotes in-depth participation in more interdependent communities. It extends the territory comprised within the boundaries of empathy.

How Image Congruity and Satisfaction Impact Customer Retention at Luxury Restaurants: A Moderated Mediation Framework

2018 ◽  
Vol 46 (6) ◽  
pp. 891-904 ◽  
Author(s):  
Heesup Han ◽  
Wansoo Kim ◽  
Sanghyeop Lee ◽  
Hye-Ran Kim
Keyword(s):  
Customer Satisfaction ◽  
Structural Model ◽  
Customer Retention ◽  
Measurement Model ◽  
Restaurant Industry ◽  
Model Assessment ◽  
Product Consumption ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

We investigated the impact of customers' image congruity and their satisfaction on customer retention at luxury restaurants. We examined the conspicuousness of product consumption as the moderator in the relationship of image congruity and customer satisfaction. Our assessment of the measurement model revealed acceptable levels of reliability and construct validity. Our findings from the structural model assessment indicated that both image congruity and customer satisfaction exerted an influence on customer retention that was sufficiently significant to explain the total variance in retention. In addition, results showed that customer satisfaction was prominent in determining retention, acting as a significant mediator. Conspicuousness of product consumption was a significant moderator of the relationship between image congruity and customer satisfaction. Overall, our findings offer researchers and practitioners in the luxury restaurant industry valuable information regarding customer retention.

Study on the Integrated Design of Underground Construction Lighting and Ventilation System

2011 ◽  
Vol 374-377 ◽  
pp. 702-705
Author(s):  
Wei Feng ◽  
Hui Min Li
Keyword(s):  
Numerical Simulation ◽  
Thermal Environment ◽  
Ventilation System ◽  
Integrated Design ◽  
Structure Design ◽  
Light Environment ◽  
System Model ◽  
Underground Construction ◽  
New Type

In the underground building, Light environment and thermal environment is poorer, in order to improve the problem, this paper brings forward a new type of lighting and ventilation system model; discusses the principle and characteristics of transmission; and analyses the question that influences lighting and ventilated effect in the application. Structure design and numerical simulation is the focus of the next step.

Design and analysis of a new frame-foot wall-climbing robot

2021 ◽  
pp. 095440702110402
Author(s):  
Ping Huo ◽  
Yangyang Xu ◽  
Jiangtao Yu ◽  
Yazhou Wang
Keyword(s):  
Structure Design ◽  
Working Environment ◽  
Structure Stability ◽  
Foot Wall ◽  
Climbing Robot ◽  
3D Design ◽  
Motion Equations ◽  
Solution Models ◽  
New Type ◽  
The Stability

This paper designs and develops a new type of frame-foot wall-climbing robot structure. According to the bionic principle, a new parallel telescopic leg structure is proposed, and the 3D design of the overall structure of the wall-climbing robot is completed. Secondly, the kinematics analysis of the robot is carried out, and the forward and inverse solution models of the leg structure position are completed to verify the feasibility of the leg structure stability. Based on the polynomial motion equations, the robot motion planning and gait design are established, and the speed and acceleration change graphs of the leg structure slider are obtained, which avoids the rigid impact between the parts, and realizes the alternate adsorption and continuous movement of the robot legs, which the rationality of the legs structure design and the stability of the movement are verified. Through simulation and experimental results, it is shown that during the robot’s movement, the leg structure can adjust the step distance and step height according to obstacles, so as to achieve the expected obstacle crossing goal. The leg structure is adjusted according to the working environment to ensure that the fuselage and the working surface are always kept parallel to improve the stability of the overall structure.

scholarly journals Identifying Structural Domains and Conserved Regions in the Long Non-Coding RNA lncTCF7

2019 ◽  
Vol 20 (19) ◽  
pp. 4770 ◽  
Author(s):  
Michael C. Owens ◽  
Sean C. Clark ◽  
Allison Yankey ◽  
Srinivas Somarowthu
Keyword(s):  
Structure Function ◽  
Cancer Biology ◽  
Structural Model ◽  
Structural Domains ◽  
Conserved Regions ◽  
Non Coding Rna ◽  
Function Relationship ◽  
Modular Domains ◽  
Relationship Of ◽  
Long Non Coding Rna

Long non-coding RNA (lncRNA) biology is a rapidly growing area of study. Thousands of lncRNAs are implicated as key players in cellular pathways and cancer biology. However, the structure–function relationships of these novel biomolecules are not well understood. Recent structural studies suggest that lncRNAs contain modular structural domains, which play a crucial role in their function. Here, we hypothesized that such structural domains exist in lncTCF7, a conserved lncRNA implicated in the development and progression of several cancers. To understand the structure–function relationship of lncTCF7, we characterized its secondary structure using chemical probing methods. Our model revealed structural domains and conserved regions in lncTCF7. One of the modular domains identified here coincides with a known protein-interacting domain. The model reported herein is, to our knowledge, the first structural model of lncTCF7 and thus will serve to direct future studies that will provide fundamental insights into the function of this lncRNA.

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