Design and Manufacturing of a Multi-Stable Selectively Stiff Morphing Section Demonstrator

2019 ◽  
Author(s):  
D. Matthew Boston ◽  
Jose R. Rivas-Padilla ◽  
Andres F. Arrieta
Keyword(s):  
Structural Response ◽  
Experimental Results ◽  
Image Correlation ◽  
Stable States ◽  
Loading Test ◽  
Wing Section ◽  
Curved Structures ◽  
Trade Offs ◽  
Static Loading Test ◽  
And Performance

Abstract Morphing wings offer potential efficiency and performance benefits for aircraft fulfilling multiple mission requirements. However, the design of shape adaptable wings is limited by the inherent design trade-offs of weight, aerodynamic control authority, and load-carrying capacity. A potential solution to this trilemma is proposed by exploiting the stiffness adaptability of thin, curved structures which geometric instability results in two statically stable states. We design and manufacture a morphing wing section demonstrator composed of two compliant 3D printed ribs monolithically embedded with the proposed bi-stable elements. The demonstrator’s structural response is numerically modelled and compared with experimental results from a static loading test. A deflection field of the response under mechanical actuation is obtained through digital image correlation. Numerical and experimental results indicate the capability of the wing section to achieve four distinct stable configurations with varying global stiffness behavior.

Analysis and Test on Mechanical Properties of a Flexible Suspension Bridge

2013 ◽  
Vol 405-408 ◽  
pp. 1616-1622
Author(s):  
Guo Hui Cao ◽  
Jia Xing Hu ◽  
Kai Zhang ◽  
Min He
Keyword(s):  
Mechanical Properties ◽  
Suspension Bridge ◽  
Experimental Results ◽  
Suspension Bridges ◽  
Loading Test ◽  
Main Cable ◽  
Element Simulation ◽  
Static Loading Test ◽  
Geometric Nonlinear Analysis ◽  
Test Process

In order to research on mechanical properties of flexible suspension bridges, a geometric nonlinear analysis method was used to simulate on the experimental results, and carried on static loading test finally. In the loading test process, the deformations were measured in critical section of the suspension bridge, and displacement values of measured are compared with simulation values of the finite element simulation. Meanwhile the deformations of the main cable sag are observed under classification loading, the results show that the main cable sag increment is basically linear relationship with the increment of mid-span loading and tension from 3L/8 and 5L/8 to L/2 section, the main cable that increasing unit sag required mid-span loads and tension are gradually reduce in near L/4 and 3L/4 sections and gradually increase in near L/8 and 7L/8 sections and almost equal in near L/2, 3L/8 and 5L/8 sections. From the experimental results, the flexible suspension bridge possess good mechanical properties.

Study on TMD for Long Period Structure Using Air Floating Technique: Investigation of Fundamental Performance

2018 ◽  
Author(s):  
Osamu Furuya ◽  
Hiroshi Kurabayashi ◽  
Osamu Takahashi ◽  
Kunio Sanpei ◽  
Shoichi Sakamoto ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Shaking Table Test ◽  
Structural Response ◽  
Shaking Table ◽  
Inertia Force ◽  
Loading Test ◽  
Natural Period ◽  
Long Period ◽  
Static Loading Test

Natural period of architectural structure have been longer to be high-rise in recent years. Tuned Mass Damper (TMD) is applied for the structural response reduction in such a long period structure. In general since there are a lot of design cases using a guide rail for linear motion guide of the mass in TMD, the friction coefficient in assembled TMD becomes almost from 3/1000 to 5/1000. The friction coefficient leads an important problem in view point of performance design for long period structures because of that the friction force becomes a large compared with starting inertia force. In this study, new type TMD with air pressure floating technique has been examined to reduce a friction force for starting inertia force, and to set 0.01 m/s2 in starting acceleration as a performance target. This paper shows the evaluation results for fundamental performance from static loading test and shaking table test.

FXY: A HIERARCHICAL ROUTING ALGORITHM TO BALANCE PERFORMANCE AND FAULT TOLERANCE IN NETWORKS-ON-CHIP

2014 ◽  
Vol 23 (10) ◽  
pp. 1450146 ◽  
Author(s):  
SALEH FAKHRALI ◽  
HAMID R. ZARANDI
Keyword(s):  
Fault Tolerance ◽  
Fault Tolerant ◽  
Routing Algorithm ◽  
Experimental Results ◽  
Balance Performance ◽  
Networks On Chip ◽  
Large Size ◽  
Trade Offs ◽  
And Performance ◽  
On Chip

This paper presents a hierarchical fault-tolerant routing algorithm called FXY, which is a hybrid method based on flooding and XY, and can balance performance and fault tolerance based on a predefined parameter m. First, FXY partitions the whole network into different equal size square submeshes with the size of m × m. At the first level of the hierarchy, packet routing within these submeshes is performed based on flooding routing algorithm. When the packets are received at effective boundary of each submesh, XY routing is performed to route the packet inter submeshes i.e., from one submesh to the neighbor submesh which is certainly one of its neighbor nodes. Here, the size of the submesh is defined as fault-tolerant granularity. As fault-tolerant granularity is increased, the size of the submeshes will be increased, therefore the method mainly floods packets in large-size submeshes and finally packets are received at their destinations correctly. On the other hand, when fault-tolerant granularity is decreased, the method mainly routes packets as XY method, which is not fault-tolerant, but has the best performance. The method is evaluated for various packet injection rates and fault rates. The experimental results reveal that the method presents a fault-tolerant routing algorithm, and can be adjusted so that it shows better fault-tolerance and performance trade-offs compared to XY and flooding which are two end-to-end cases of having the best performance and no fault-tolerance, having the least performance and the best fault tolerance, respectively. The experimental results for an 8 × 8 NoC size, have shown that 2-FXY, which is the proposed method with fault-tolerant granularity of two, offers the best trade-off between performance and fault tolerance compared to other methods, XY, flooding and probabilistic flooding.

Prediction, Testing, and Analysis of a 50 m Long Pile in Soft Marine Clay

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Bengt Fellenius
Keyword(s):  
Peak Load ◽  
Pile Head ◽  
Marine Clay ◽  
Loading Test ◽  
Head Displacement ◽  
Floating Pile ◽  
Peak Loads ◽  
Static Loading Test ◽  
Beta Coefficient ◽  
Load Movement

On April 4, 2018, 209 days after driving, a static loading test was performed on a 50 m long, strain-gage instrumented, square 275-mm diameter, precast, shaft-bearing (“floating”) pile in Göteborg, Sweden. The soil profile consisted of a 90 m thick, soft, postglacial, marine clay. The groundwater table was at about 1.0 m depth. The undrained shear strength was about 20 kPa at 10 m depth and increased linearly to about 80 kPa at 55m depth. The load-distribution at the peak load correlated to an average effective stress beta-coefficient of 0.19 along the pile or, alternatively, a unit shaft shear resistance of 15 kPa at 10 m depth increasing to about 65 kPa at 50 m depth, indicating an α-coefficient of about 0.80. Prior to the test, geotechnical engineers around the world were invited to predict the load-movement curve to be established in the test—22 predictions from 10 countries were received. The predictions of pile stiffness, and pile head displacement showed considerable scatter, however. Predicted peak loads ranged from 65% to 200% of the actual 1,800-kN peak-load, and 35% to 300% of the load at 22-mm movement.

Platform Independent Analysis of Probabilities on Multithreaded Programs

2013 ◽  
Vol 1 (3) ◽  
pp. 48-65
Author(s):  
Yuting Chen
Keyword(s):  
Operating System ◽  
Static Analysis ◽  
Main Idea ◽  
Experimental Results ◽  
Machine To Machine ◽  
Concurrent Program ◽  
Acceptable Accuracy ◽  
Multithreaded Programs ◽  
Independent Analysis ◽  
And Performance

A concurrent program is intuitively associated with probability: the executions of the program can produce nondeterministic execution program paths due to the interleavings of threads, whereas some paths can always be executed more frequently than the others. An exploration of the probabilities on the execution paths is expected to provide engineers or compilers with support in helping, either at coding phase or at compile time, to optimize some hottest paths. However, it is not easy to take a static analysis of the probabilities on a concurrent program in that the scheduling of threads of a concurrent program usually depends on the operating system and hardware (e.g., processor) on which the program is executed, which may be vary from machine to machine. In this paper the authors propose a platform independent approach, called ProbPP, to analyzing probabilities on the execution paths of the multithreaded programs. The main idea of ProbPP is to calculate the probabilities on the basis of two kinds of probabilities: Primitive Dependent Probabilities (PDPs) representing the control dependent probabilities among the program statements and Thread Execution Probabilities (TEPs) representing the probabilities of threads being scheduled to execute. The authors have also conducted two preliminary experiments to evaluate the effectiveness and performance of ProbPP, and the experimental results show that ProbPP can provide engineers with acceptable accuracy.

scholarly journals Research and development of thick rubber bearing for SFR (Design formulas for thick rubber bearing based on static loading test utilized scale model)

2017 ◽  
Vol 83 (852) ◽  
pp. 17-00050-17-00050 ◽  
Author(s):  
Tsuyoshi FUKASAWA ◽  
Shigeki OKAMURA ◽  
Tomohiko YAMAMOTO ◽  
Nobuchika KAWASAKI ◽  
Satoru INABA ◽  
...  
Keyword(s):  
Research And Development ◽  
Static Loading ◽  
Scale Model ◽  
Loading Test ◽  
Rubber Bearing ◽  
Static Loading Test

Specialization and performance trade‐offs across hosts in cactophilic Drosophila species

2021 ◽  
Author(s):  
Santiago Bouzas ◽  
María F. Barbarich ◽  
Eduardo M. Soto ◽  
Julián Padró ◽  
Valeria P. Carreira ◽  
...  
Keyword(s):  
Drosophila Species ◽  
Cactophilic Drosophila ◽  
Trade Offs ◽  
And Performance

scholarly journals Noise and Breakdown Characterization of SPAD Detectors with Time-Gated Photon-Counting Operation

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5287
Author(s):  
Hiwa Mahmoudi ◽  
Michael Hofbauer ◽  
Bernhard Goll ◽  
Horst Zimmermann
Keyword(s):  
Breakdown Voltage ◽  
Single Photon ◽  
Photon Counting ◽  
Low Noise ◽  
Dark Count ◽  
Fully Integrated ◽  
Trade Offs ◽  
And Performance ◽  
Noise Models

Being ready-to-detect over a certain portion of time makes the time-gated single-photon avalanche diode (SPAD) an attractive candidate for low-noise photon-counting applications. A careful SPAD noise and performance characterization, however, is critical to avoid time-consuming experimental optimization and redesign iterations for such applications. Here, we present an extensive empirical study of the breakdown voltage, as well as the dark-count and afterpulsing noise mechanisms for a fully integrated time-gated SPAD detector in 0.35-μm CMOS based on experimental data acquired in a dark condition. An “effective” SPAD breakdown voltage is introduced to enable efficient characterization and modeling of the dark-count and afterpulsing probabilities with respect to the excess bias voltage and the gating duration time. The presented breakdown and noise models will allow for accurate modeling and optimization of SPAD-based detector designs, where the SPAD noise can impose severe trade-offs with speed and sensitivity as is shown via an example.

Renewable energy selection based on a new entropy and dissimilarity measure on an interval-valued neutrosophic set

2021 ◽  
pp. 1-18
Author(s):  
ShuoYan Chou ◽  
Truong ThiThuy Duong ◽  
Nguyen Xuan Thao
Keyword(s):  
Decision Making ◽  
Renewable Energy ◽  
Membership Function ◽  
Fossil Fuels ◽  
Multiple Criteria Decision Making ◽  
Clean Energy ◽  
Dissimilarity Measure ◽  
Neutrosophic Set ◽  
Trade Offs ◽  
And Performance

Energy plays a central part in economic development, yet alongside fossil fuels bring vast environmental impact. In recent years, renewable energy has gradually become a viable source for clean energy to alleviate and decouple with a negative connotation. Different types of renewable energy are not without trade-offs beyond costs and performance. Multiple-criteria decision-making (MCDM) has become one of the most prominent tools in making decisions with multiple conflicting criteria existing in many complex real-world problems. Information obtained for decision making may be ambiguous or uncertain. Neutrosophic is an extension of fuzzy set types with three membership functions: truth membership function, falsity membership function and indeterminacy membership function. It is a useful tool when dealing with uncertainty issues. Entropy measures the uncertainty of information under neutrosophic circumstances which can be used to identify the weights of criteria in MCDM model. Meanwhile, the dissimilarity measure is useful in dealing with the ranking of alternatives in term of distance. This article proposes to build a new entropy and dissimilarity measure as well as to construct a novel MCDM model based on them to improve the inclusiveness of the perspectives for decision making. In this paper, we also give out a case study of using this model through the process of a renewable energy selection scenario in Taiwan performed and assessed.

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