Reinforced thermoplastic fasteners

2021 ◽  
pp. 135-148
Author(s):  
А.В. Чесноков ◽  
В.Н. Андреев ◽  
И.А. Тимофеев
Keyword(s):  
Tensile Strength ◽  
Truss Structures ◽  
Load Bearing ◽  
Domestic Production ◽  
Aerospace Technology ◽  
Reinforced Thermoplastics

Обоснована актуальность применения армированных термопластов для изготовления крепежа для аэрокосмической техники. Разработана технология получения крепежа для соединения трехслойных панелей из угленаполненного (40%) полиэфирэфиркетона импортного и отечественного производства. Проведены исследования полученного крепежа. Полученные результаты применены в разработке технологии изготовления крепежа для несущих ферменных конструкций поддерживающих кабельную разводку на космических аппаратах. Средняя удельная прочность крепежа на разрыв составляет 115 МПа·см/г, что определяет перспективность применения его в конструкциях аэрокосмической техники. На крепеж получены Технические условия «Детали крепежные армированные». The relevance of the use of reinforced thermoplastics for the manufacture of fasteners for aerospace equipment is substantiated. A technology has been developed for obtaining fasteners for joining three-layer panels made of carbon-filled (40%) polyetheretherketone of foreign and domestic production. The research of the received fasteners has been carried out. The results obtained are used in the development of a technology for the manufacture of fasteners for load-bearing truss structures that support cabling on spacecraft. The average specific tensile strength of the fastener is 115 MPa cm/g, which determines the prospects of its application in the structures of aerospace technology. The technical conditions «Reinforced fastening parts» were received for the fasteners.

FINITE ELEMENT ANALYSES ON CORRODED PONY TRUSS BRIDGE FOR REASONABLE MAINTENANCE

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Risa Fujinaga ◽  
Tatsumasa Kaita ◽  
Ryoko Koyama ◽  
Tsutomu Imai ◽  
Katashi Fujii
Keyword(s):  
Bearing Capacity ◽  
Ultimate Load ◽  
Plane Deformation ◽  
Element Model ◽  
Truss Structures ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Out Of Plane ◽  
Pony Truss Bridge ◽  
Truss Bridge

The load bearing capacity of an existing corroded pony truss bridge, which is used for 100 years was estimated from FEM results for whole bridge model. The beam element model is to clarify that the influence of the residual out-of-plane deformation in main truss structures on the load bearing capacity from the viewpoint of whole bridge. Also, shell element model is to clarify that the influence of severe corrosion damages occurred in many structural members on the load bearing capacity as whole bridge. On the other hand, the influence of assumed support conditions in analytical models were discussed from the analytical results of both type of models, because it will be thought that the performance of shoes deteriorates gradually by long in-service period. The ultimate load bearing capacity was estimated by the critical live load magnification. From the analytical results, the residual out-of-plane deformation of main truss structures in this bridge had little influence on the ultimate load bearing capacity. Also, the ultimate load bearing capacity may decrease up to 20% due to aging deterioration of shoes including corrosion damages. In bridge maintenance, it should be paid attention on local severe corrosion damages on the structural member, which may occur higher secondary stress.

scholarly journals Cellulose Fiber-Reinforced PLA versus PP

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Nina Graupner ◽  
Jörg Müssig
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Load Transfer ◽  
Cellulose Fiber ◽  
Fiber Reinforced ◽  
Strain Behavior ◽  
The Matrix ◽  
Lyocell Fibers ◽  
Reinforced Thermoplastics ◽  
The Impact

The present study focuses on a comparison between different cellulose fiber-reinforced thermoplastics. Composites were produced with 30 mass-% lyocell fibers and a PLA or PP matrix with either an injection (IM) or compression molding (CM) process. Significant reinforcement effects were achieved for tensile strength, Young’s modulus, and Shore D hardness by using lyocell as reinforcing fiber. These values are significantly higher for PLA and its composites compared to PP and PP-based composites. Investigations of the fiber/matrix adhesion show a better bonding for lyocell in PLA compared to PP, resulting in a more effective load transfer from the matrix to the fiber. However, PLA is brittle while PP shows a ductile stress-strain behavior. The impact strength of PLA was drastically improved by adding lyocell while the impact strength of PP decreased. CM and IM composites do not show significant differences in fiber orientation. Despite a better compaction of IM composites, higher tensile strength values were achieved for CM samples due to a higher fiber length.

Tensile Behavior of Polypropylene Reinforced with Comminutes Extracted from Out-of-Condition Aerospace Grade Carbon Fiber Prepreg Waste

2015 ◽  
Vol 761 ◽  
pp. 526-530
Author(s):  
Noraiham Mohamad ◽  
Anisah Abd Latiff ◽  
Mohamad Azrul Drahman ◽  
Siti Rahmah Shamsuri ◽  
Jeeferie Abdil Razak ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
End Of Life ◽  
High Performance ◽  
Industry Waste ◽  
Melt Compounding ◽  
C 50 ◽  
Reinforced Thermoplastics ◽  
Internal Mixer

Carbon fiber reinforced thermoplastics are in demand for high performance composites, particularly for the aircraft industry. Waste disposal of carbon fiber in the form of off-cuts, out of life of prepreg and end-of-life components lead to the environmental pollution. This study focuses on the processing and characterization of carbon fiber prepreg comminutes reinforced polypropylene (PP) produced by melt compounding using an internal mixer. In this study, end-of-life carbon fiber prepreg were crushed into fine fibers and dried in oven at 220°C for one hour. It was divided into two types; (1) partially cured carbon fiber prepreg (c-CFP) and, (2) fully cured carbon fiber prepreg (c-CF). The composites were prepared by melt compounding in a Haake internal mixer at 180°C, 50 rpm for 10 minutes. Samples were tested for tensile properties (ASTM D638) and the morphology of fractured surface was observed using Scanning Electron Microscopy (SEM). Increasing carbon fiber in polypropylene was found to increase the Young’s modulus of the composites, but decreased the tensile strength. However, the tensile strength of composites with c-CFP were observed to surpass the neat PP at every loading level. Whereas for composites with c-CF the tensile strength was comparable to the neat PP only within the range of 3 – 5 wt.%.

OPTIMIZATION OF TRUSS STRUCTURES WITH CHORDS OF STEP-VARIABLE CROSSSECTIONS MADE OF RECTANGULAR PIPES

2021 ◽  
Vol 295 (2) ◽  
pp. 53-61
Author(s):  
A.S. Marutyan ◽  
Keyword(s):  
Cross Sections ◽  
Welded Joints ◽  
Optimization Problems ◽  
Truss Structures ◽  
Technical Solution ◽  
Variable Cross ◽  
Load Bearing ◽  
Strength Tests ◽  
The Difference

The article describes the regularity of the optimization calculation of unification zones in relation to beam chords of step-variable cross-sections with the determination of their design coefficients. The rationality of the formation of these chords in truss structures made of rectangular pipes is shown due to the difference not in the heights of the sections, but in their thicknesses with welded joints on the longitudinal slits.The engineering method for calculating such joints, as well as their load-bearing capacity, has been tested by tensile strength tests of the samples.The universality of the technical solution of welded joints with slits ensures their use in structures made of tubular and rolled profiles, and it preserves the accepted layout of standardized trusses with assemblies and flanged connections. The significant reduction in structural material (steel) in standardized trusses made of bent-welded profiles was revealed when chords of uniform cross-sections were replaced with chords of step-variable cross-sections. The article also gives the comparative calculation of the design coefficients and the averaged coefficients of chord elements use when the lengths of the unification zones and the belt panels coincide. Sufficient correctness of the approximate calculation method for solving optimization problems and variant design of load-bearing structures is confirmed.

Predicting the tensile strength of natural fibre reinforced thermoplastics

2007 ◽  
Vol 67 (11-12) ◽  
pp. 2454-2466 ◽  
Author(s):  
Angelo G. Facca ◽  
Mark T. Kortschot ◽  
Ning Yan
Keyword(s):  
Tensile Strength ◽  
Natural Fibre ◽  
Reinforced Thermoplastics

scholarly journals Inherent Adaptive Structures Using Nature-Inspired Compound Elements

2020 ◽  
Vol 6 ◽  
Author(s):  
Mohammad Reza Chenaghlou ◽  
Mohammad Kheirollahi ◽  
Karim Abedi ◽  
Ahmad Akbari ◽  
Aydin Fathpour
Keyword(s):  
Bearing Capacity ◽  
Steel Tube ◽  
Truss Structures ◽  
Load Bearing Capacity ◽  
Element Analysis ◽  
Load Bearing ◽  
Natural Systems ◽  
Long Span ◽  
Steel Core ◽  
Bamboo Stem

Biomimicry studies have attracted significant attention in research and practice, leading to effective engineering solutions to develop new types of structures inspired by natural systems. The objective of this study is to employ natural structures' inherent adaptivity under changing loading conditions. Three new types of compound elements are proposed that are able to improve the structure load-bearing capacity through passive inherent adaptivity. A self-centering system, inspired by the human spine, which comprises a column pre-stressed through cables, is employed as a kinematic isolator. A similar self-centering system is applied to increase the load-bearing capacity of unreinforced masonry columns. An axially loaded element, inspired by the bamboo stem, which comprises a steel core reinforced by a series of cylindrical plates that are encased in a steel tube, is employed to control the onset of instability in long-span truss structures. Application to typical frame, masonry, and truss structures is investigated through finite element analysis. Results show that the proposed compound elements are effective to increase the structure load-bearing capacity and to reduce the response under seismic excitation owning to their inherent adaptive features.

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