3,684 research outputs found
[List of Colored Identification Pins #2]
No full textList of colored identification pins used to designate personnel assignments, by an unknown author
Improving bearing performance of composite bolted joints using z-pins
No full textThe effect of z-pins on the bearing properties and damage tolerance of composite bolted joints is experimentally studied in this paper. The region around bolt-holes in carbon/epoxy laminates was reinforced in the through-thickness direction with different volume contents and sizes of fibrous z-pins. Bearing test results show that the z-pins improved the bearing stiffness (by 7.5¿9.6%), ultimate load (7.7¿12.8%), failure strength (7.4¿9.8%), and elastic strain energy absorption to bearing failure (8.5¿16.3%) of the composite joints. The bearing properties increased at a quasi-linear rate with the z-pin content, but were not dependent on pin diameter. Stiffness is improved by z-pins increasing the through-thickness tensile modulus around the bolt-hole of the joint. Post-mortem microstructural examination of the failed joint specimens revealed that z-pins improve the bearing strength by reducing cracking near the bolt-hole via an interlaminar bridging toughening mechanism that involves debonding and frictional sliding of pins within the damaged region. The elastic strain energy to failure is increased by the through-thickness stiffening and toughening provided by the z-pins. This study proves that the reinforcement of bolt-holes with z-pins increases the bearing properties without the weight penalty incurred with the traditional strengthening method of thickening the laminate around holes
Fatigue delamination behaviour of unidirectional carbon fibre/epoxy laminates reinforced by Z-Fiber® pinnin
No full text-Pin reinforced carbon-fibre epoxy laminates were tested under Mode I and Mode
II conditions, both quasi-statically and in fatigue. Test procedures were
adapted from existing standard or pre-standard tests. Samples containing 2% and
4% areal densities of carbon-fibre Z-pins (0.28mm diameter) were compared with
unpinned laminates. Quasi-static tests under displacement control yielded a
dramatic increase of the apparent delamination resistance. Specimens with 2% pin
density failed in Mode I at loads 170N, equivalent to an apparent GIC of 2kJ/m2.
Fatigue testing under load control showed that the presence of the through-
thickness reinforcement slowed down fatigue delamination propagation
Pictures of the South - Sheridan's Ten-Pins
No full textPhotograph shows engraving, from a drawing by Theodore R. Davis, of a group of people bowling at ten-pins. Sheridan referred to is General Phil Sheridan who had his headquarters in New Orleans during Reconstruction
Jacksonville Jazz Festival Pins
No full textAssorted souvenir pins. Top: (l-r): 1985, 1986, 1990, and undated [possibly 2004]. Bottom (l-r): 2005,2006,2007 and 2010.https://digitalcommons.unf.edu/jacksonville_jazz_images/1018/thumbnail.jp
Dean and Mrs. Sherwood R. Mercer Giving Wishbone Pins to Student Wives. 1973
No full textDean and Mrs. Sherwood R. Mercer Giving Wishbone Pins to Student Wiveshttps://digitalcommons.pcom.edu/secure_merit/1053/thumbnail.jp
Col. Bodine, pins Commendation on Capt. Sedlacek
No full textCol. Donald R. Bodine, Director, Officers Dept., Fort Monmouth, N.J., pins Commendation ribbon with Metal Pendant on Capt. Leroy V. Sedlacek, Officers Dept
Medals and pins
No full textMedals and pins. Handritten below photograph: Pick out yours. [Full page images can be found in Box 1 scrapbook, also in this image gallery.]https://egrove.olemiss.edu/cofield/1358/thumbnail.jp
V.—<i>Irish Bronze Pins of the Christian Period</i>
No full textA classification of the numerous bronze pins found in Ireland is to be desired. Wilde, who figured over thirty specimens of various kinds, made no separation between Bronze and Early Iron Age pins and those of the Christian period. Coffey devoted some pages to pins, reproducing a number of Wilde's illustrations; he did not, however, attempt any classification, merely stating that, with the exception of the ‘hand-type’ and other pins of that class showing decoration earlier than the interlaced style, the approximate date of the majority might be taken as the tenth to the eleventh century.</jats:p
Analysis of Periodic Structures Made of Pins Inside a Parallel Plate Waveguide
No full textSpecial Issue: Higher Symmetries and Its Application in Microwave Technology, Antennas and MetamaterialsIn this work, we have analyzed different versions of periodic structures made with metallic pins located inside a parallel plate waveguide (PPWG), varying the symmetry and disposition of the pins. The analysis focuses on two main parameters related to wave propagation. On one hand, we have studied how the different proposed structures can create a stopband so that the parallel plate modes can be used in gap waveguide technology or filtering structures. On the other hand, we have analyzed the dispersion and equivalent refractive index of the first propagating transverse electromagnetic mode (TEM). The results show how the use of complex structures made with pins in the top and bottom plates of a PPWG have no advantages in terms of the achieved stopband size. However, for the case of the propagating mode, it is possible to find less dispersive modes and a higher range of equivalent refractive indices when using double-pin structures compared to a reference case with single pins.This research was funded by the Spanish Ministerio de Ciencia, Innovación y Universidades grant number [TEC2016-79700-C2-2-R], Becas Santander Jóvenes Investigadores and FONDECYT 11180434
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