scholarly journals Soft Origami Gripper with Variable Effective Length

2021 ◽  
pp. 2000251
Author(s):  
Bohan Chen ◽  
Zhuyin Shao ◽  
Zhexin Xie ◽  
Jiaqi Liu ◽  
Fei Pan ◽  
...  
Keyword(s):  
Effective Length

scholarly journals Withdrawal Properties of Self-Tapping Screws in Japanese larch (Larix kaempferi (Lamb.) Carr.) Cross Laminated Timber

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 524
Author(s):  
Junhua Xu ◽  
Shuangbao Zhang ◽  
Guofang Wu ◽  
Yingchun Gong ◽  
Haiqing Ren
Keyword(s):  
Regression Model ◽  
Engineering Design ◽  
Wood Species ◽  
Japanese Larch ◽  
Effective Length ◽  
Larix Kaempferi ◽  
Cross Laminated Timber ◽  
The World ◽  
Different Types ◽  
Length Increment

With the increasing popularity of cross-laminated timber (CLT) constructions around the world, there have been attempts to produce CLT using local wood species in different countries, such as Japanese larch (Larix kaempferi (Lamb.) Carr.) in China. Thus, the need to investigate the connection performance also increases to support the design and construction of CLT buildings using local wood species. In this study, the withdrawal properties of three different types of self-tapping screws (STS), with a diameter of 6 mm, 8 mm, and 11 mm, were tested with Japanese larch CLT. The results revealed that the withdrawal strength of STS increased with increasing density and effective length, but decreased with an increasing diameter. With a density increment of 0.05 g/cm3, the withdrawal strength increased by an average of 9.4%. With an effective length increment of 24 mm, the withdrawal strength increased by an average of 1.4%. An empirical regression model was adopted to predict the withdrawal strength of Japanese larch CLT based on the results, which can be used for potential engineering design of CLT connections using STS.

On the effective length of the top piston ring involved in hydrodynamic lubrication

2005 ◽  
Vol 17 (3) ◽  
pp. 309-318 ◽  
Author(s):  
V. D'agostino ◽  
S. Della Valle ◽  
A. Ruggiero ◽  
A. Senatore
Keyword(s):  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Effective Length

Buckling of Double Layer Grid Edge Members

1997 ◽  
Vol 12 (2) ◽  
pp. 81-87
Author(s):  
Erling Murtha-Smith ◽  
Thuyen P. Nguyen
Keyword(s):  
Double Layer ◽  
External Load ◽  
Stiffness Matrix ◽  
Diagonal Matrix ◽  
Moment Of Inertia ◽  
Effective Length ◽  
Stiffness Coefficient ◽  
Stability Functions

Stability equations are developed for edge joints for Double Layer Grids. Translations are neglected and rotations at each joint are related. Hence, the stiffness matrix reduces to a diagonal matrix of unit bandwidth so each joint becomes an independent substructure. Instability of an edge joint occurs when the minimum principal stiffness coefficient of the joint goes to zero. Using stability functions and the regular geometric relationships of DLG topology, the buckling forces in the members and hence the external load on the system are determined. A simple example in which the members were all of the same length, material and moment of inertia, gives effective length factors for the edge members of between 0.77 to 0.81.

Wing Folding in Lepidoptera

1964 ◽  
Vol 96 (1-2) ◽  
pp. 148-149 ◽  
Author(s):  
Janet Sharplin
Keyword(s):  
Posterior Margin ◽  
Anterior Margin ◽  
Effective Length ◽  
Wing Base ◽  
The Third ◽  
Binocular Microscope ◽  
Axillary Sclerites ◽  
Median Plate ◽  
Micrometer Eyepiece ◽  
Wing Folding

The wing folding mechanism was investigated after a detailed study of the wing base morphology had been made (Sharplin, Canad. Ent. 95: 1024; 1121). Living moths were observed with a binocular microscope equipped with a micrometer eyepiece.The first and second axillary sclerites do not move anteroposteriorly; only the distal half of the wing base is involved in wing folding. The folding muscle originates on the pleural ridge and inserts on the third axillary sclerite. The movement of the third axillary is communicated to the bases of the anterior veins through the median plates. The radial plate rotates around the ventral second axillary sclerite which lies underneath the radial bridge at point p, (Fig. 1). Bending cuticle allows the radial bridge to buckle when the wing is folded. The first median plate ( Ml ) rotates about its articulation ( f ) with the dorsal second axillary sclerite. The distal median plate (M2) passes underneath the second cubitus and is fused to the radius. This connection to the radius restricts the backward movement of the second median plate so that point e instead of following the wider arc eg of a circle with its centre at f, must follow the arc cegd drawn about pivot p. The median plates are bent upwards during wing folding and their effective length is shortened so that they can follow the shallow arc epg. When point e is in position g the posterior margin of the median plates is straight, although the anterior margin remains arched causing the median plates to be buckled, (Fig. 2).

Comparison Between the Effects of Zero and Non-Zero Flow Acceleration on the Entropy Wave Decay: An Experimental Study

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
S. M. Hosseinalipour ◽  
E. Rahmani ◽  
A. Fattahi
Keyword(s):  
Hot Spot ◽  
Theoretical Models ◽  
Fast Response ◽  
Effective Length ◽  
Combustion Instabilities ◽  
Convergent Nozzle ◽  
Flow Acceleration ◽  
Wave Decay ◽  
Accelerated Flow ◽  
Effective Length Method

Abstract Entropy wave, as the convecting hot spot, is one of the sources of combustion instabilities, which is less explored through the literature. Convecting in a highly turbulent flow of a combustor, entropy waves may experience some levels of dissipation and deformation. In spite of some earlier investigations in the zero acceleration flow, the extent of the wave decay has not been clear yet. Further, there exist no results upon the wave decay in non-zero accelerated flows. This is of crucial importance, as the wave passes through the end nozzle of the combustor or gas turbine stages. The current experiment, therefore, compares the wave decay in both flow of constant and variable bulk velocity, meaning, respectively, a uniform pipe and a convergent nozzle. The comparison will aid the theoretical models to reduce complexity by simplifying the relations of non-zero acceleration flow to those of no acceleration, as followed by the earlier effective-length method. Reynolds number and inlet turbulence intensity are considered as the governing hydrodynamic parameters for both investigated flows. The entropy wave is generated by an electrical heater module and detected using fast-response thermocouples. The results show that the entropy wave variation is point-wise and frequency-dependent. The accelerated flow of the nozzle is generally found to be more dissipative in comparison with the zero acceleration flow.

The Lima earthquake of October 3, 1974: Damage distribution

1977 ◽  
Vol 67 (5) ◽  
pp. 1441-1472
Author(s):  
R. Husid ◽  
A. F. Espinosa ◽  
J. de las Casas
Keyword(s):  
Reinforced Concrete ◽  
Structural Damage ◽  
Concrete Structures ◽  
Effective Length ◽  
Reinforced Concrete Structures ◽  
Severe Damage ◽  
Original Design ◽  
Reinforced Masonry ◽  
Water Tanks ◽  
Story Building

abstract The October 3, 1974, earthquake caused severe damage to buildings of adobe and quincha construction, and also to masonry, reinforced masonry, and reinforced-concrete structures in Lima and vicinity. Most of the damage to well-built structures was due, in part, to the lack of lateral resistance in the original design and to the fact that this earthquake had more energy around 0.4 seconds period than prior destructive earthquakes. Water tanks on the roofs of structures with four or five stories were damaged. Well-engineered single-story buildings were less affected than taller structures. Considerable structural damage to reinforced-concrete structures occurred in the districts of Barranco, La Campiña Molina, and Callao. In La Campiña three-story building partly collapsed and other buildings sustained considerable damage. In La Molina, the buildings of the Agrarian University sustained severe damage, and some collapsed. In Surco, the district adjacent to La Molina, there was no appreciable damage. In Callao, a four-story building collapsed, and the upper half of a concrete silo collapsed. In reinforced-concrete structures, column ties were frequently small in diameter, widely spaced, and not well connected. Usually, the reinforcement of resisting elements had no relation to their stiffnesses. Front columns in school buildings were restrained by high brick walls and had rather short effective lengths to allow building displacement in that direction. The windows in the rear walls gave the rear columns a much greater effective length. Therefore, a longitudinal displacement induces large shear forces in the front columns where most of the severe damage occurred. This problem was not considered in the design of these structures.

Performance comparison between dual cantilevered and touch based hybridized triboelectric harvesters

2021 ◽  
Vol 15 (1) ◽  
pp. 7754-7761
Author(s):  
Satish Rao Ganapathy ◽  
H. Salleh
Keyword(s):  
Low Power ◽  
Surface Area ◽  
Peak Power ◽  
Energy Harvester ◽  
Dissimilar Materials ◽  
Performance Comparison ◽  
Effective Length ◽  
Surface Charges ◽  
Generate Surface ◽  
Power Outputs

The demand for energy harvesting technologies has been increasing over the years attributed to its significance to low power applications. One of the key problems associated with the vibration-based harvester is the fact that these harvesters generate low usable power while maximum peak power can only be attained when the device frequency matches the source frequency. In this study, triboelectric mechanism was investigated in combination with the piezoelectric mechanism in order to enhance the performance of the harvester. Triboelectric mechanism functions in a way that two dissimilar materials were placed in contact and then separated in order to generate surface charges and electric potential between them. Main design factors such as materials, surface area, structure, effective length, and etc. play a significant part in the enhancement of the performance. This study proposed two distinct designs of dual cantilevered structure and touch-based triboelectric energy harvester and evaluated the efficiency of the output between both structures. In addition, the effect of extension and surface area of triboelectric materials was investigated while the influence of these factors on the performance of the harvester was evaluated. The highest value of peak power obtained for dual cantilevered hybrid harvester was 650 µW across a load of 160 kΩ and frequency of 26 Hz. On the other hand, touch-based energy harvester produced an output peak power of 1220 µW across a load of 400 kΩ at 25 Hz. Achieving these power outputs may be able to power up electronics such as smartwatches, hearing aid and etc. Future studies on reliable low power applications to further advance the green power technology will be investigated.

Sign in / Sign up

Export Citation Format

Share Document