Web Arrangements Research Articles

Fibre Blend and Web Arrangement for Optimized Dust-Holding, Hydrophobic, and Thermal Properties of Needle-Punched Nonwovens

PM2.5 filters with hydrophobicity and thermal resistance are preferable for automobile cabins, engine air intake, and indoor applications, safeguarding against moisture ingress, microbial growth, and temperature fluctuations, and ensuring optimal air quality. This study explored the effects of blending five fibres with different web arrangements and fibre blend compositions on needle-punched dust-holding, hydrophobic, and thermal properties. Polyphenylene sulfide (PPS), polypropylene (PP), polyester (PET), polylactic acid (PLA), and polyacrylonitrile (PAN) were blended in different proportions to produce the samples. The method included opening, blending, carding, web laying, and needle punching to produce eight samples with cross-laid, parallel-laid, and pre-needled parallel-laid web configurations. Standard test methods were employed for the characterization. The results showed a dust holding capacity of > 3,423,000 particles/cm2, the highest WCA of 133.12°, and the highest thermal resistance of 0.24255 m2KW−1. Based on the ANOVA analysis, web arrangement and pre-needling did not have a significant impact on the hydrophobicity of the samples. N0, N1, and N2 showed similar high water contact angles (~ 126°), indicating that the hydrophobicity was more affected by the chemistry of the fibre blend than by the web structure. Turkey’s analysis of other samples strengthened this idea. However, they had a substantial impact on the porosity, air permeability, dust-holding capacity, and thermal properties at a P-value ≤ 0.05. The findings provide insightful information regarding the complex interactions among fibre content, web layout, and pre-needling to develop sophisticated needle-punched PM2.5 filters.

Blend of Fibres to Improve the Mechanical Properties of Needle-Punched Nonwovens for PM2.5 Air Filtration

This research investigated the innovative synthesis achieved through blending five distinct fibres (Polyacrylonitrile (PAN), Polyester (PET), Polylactic acid (PLA), Polypropylene (PP), and Polyphenylene sulfide (PPS)) in the production of needle-punched nonwoven fabrics tailored for air filtration applications. The study investigated the effects of needle-punched nonwovens made with up to five fibres on the physical and mechanical properties, addressing a gap in existing literature. The method involved manual and machine opening, blending, and carding of fibre s, followed by producing three samples with different web arrangements (cross laid web, parallel laid web, and pre needled parallel lad web). The study employed standard test methods to characterize physical and mechanical properties. Results indicated that web arrangement and pre-needling significantly influenced various properties, with cross and parallel-laid web arrangements having minimal impact on thickness and bursting stretch. The parallel arrangement, whether pre-needled or not, showed no significant effect on GSM, fabric density, bursting strength, tear strength, abrasion resistance, and filtration efficiency. The highest abrasion resistance, lower pressure drop, highest fabric stiffness, moderate tensile strength, and higher bursting strength were observed in a cross-web arrangement. This study contributed valuable insights into the intricate interplay of fibre composition, web arrangement, and pre-needling in the design of advanced needle-punched nonwoven fabrics for air filtration. The findings provided a nuanced understanding of how these factors collectively impact the mechanical and physical characteristics of the material, paving the way for enhanced efficiency, durability, and versatility in air filtration applications.

A repairable carbon nanotube web-based electro-thermal heater and damage sensor for aerospace applications

ABSTRACTWe previously described an efficient, lightweight and flexible electro-thermal system, based on directly drawn carbon nanotube web (CNT web), as part of an icing protection system for carbon fibre reinforced polymer (CFRP) composite aircraft structures. The location of the heating elements on critical lifting surface leading edges or nacelle intake lips makes them particularly susceptible to impact damage, which may leave no visible mark. This makes it desirable to have both a mechanism for identifying the location of damage to the CNT structure (and by inference, potential damage to the underlying CFRP) and a process for restoring the CNT heater to full operation. With the CNT web acting as a sensor, impact damage is identified by an increase in electrical resistance and, particularly, by infrared imaging, which reveals a cold spot or zone depending upon the CNT web layup. Whereas a unidirectional CNT web layup exhibits a large increase in resistance and loss of a full width band of operation, a cross ply quasi-isotropic CNT web arrangement suffers only a small increase in resistance and a loss of function that is highly localised to the damaged area. A novel methodology, based on dispersed CNT in resin, is described for repairing and reconnecting the CNT structure and restoring functionality. A CNT web-based electro-thermal element was applied to the leading edge of a representative carbon-fibre composite wing section to demonstrate the flexibility of this system.

Flexural behavior investigation of the CFS truss beams with self-piercing riveted connection

Self-piercing riveted (SPR) connections are gradually being used in cold-formed steel structures due to higher tensile strength, shear strength and connection efficiency compared to those of self- drilling connections. With the purpose of investigating the flexural behavior of truss beams with SPR connections and studying the effects of height and span, as well as diagonal web arrangement, on their flexural stiffness and ultimate bearing capacity, the symmetric vertical static load test was conducted for 5 cold-formed thin-walled truss beam specimens with SPR connections. The finite element software was adopted to simulate the test models, and the more parameters were additionally analyzed. The research indicated that the failure modes of the specimens can be divided into two types: the local strength failure mode occurred when the upper chord flange plate was cracked, the other one occurred when the rivets at joints of truss beams were stripped from the plate. The span-height ratio, spacing of web members, chord thickness and number of rivets had great influence on the flexural stiffness and ultimate bearing capacity of truss beams with SPR connections, while the thickness of web members and the arrangement of diagonal web members had less influence. The truss beam was a simply supported beam with a weak web. A theoretical formula was proposed to calculate the equivalent flexural stiffness of the truss beam with SPR connections based on parametric analysis, and it agreed with the experiment results, so the proposed theoretical formula is valid and can be applied to practical engineering.

Experimental study on joint resistance and failure modes of concrete filled steel tubular (CFST) truss girders

Concrete Filled Steel Tubular (CFST) structures are increasingly used not only for columns in tall buildings but also in the arch trusses of many arch bridges and in the truss girders of buildings and bridge decks. Therefore, the chords of Circular Hollow Section (CHS) truss arches and girders are increasingly filled with concrete, effectively making them CFST structures. In addition to the strength and stiffness of the CFST members, the failure mode of the CFST joint connecting them to the tubular member is also affected by the concrete filling. In this study, truss girders with different web arrangements were tested, and their behaviour investigated. The girders were not slender because they were designed to attain the peak limiting state for joint failure rather than chord failure due to bending moments. Moreover, two other types of girders were tested: one without concrete-filled chords (CHS girder) and another with only the upper chord filled with concrete; thus allowing an investigation of how a concrete-filled chord affects joint failure mode. The geometry of the CHS girder joints was such that only chord face failure and punching shear failure could occur. The former required an inward deformation that was prevented by the concrete filling in a CFST girder with similar geometry. Finally, the study considers extending the Eurocode 3 and the AWS D1.1 code formulae, originally proposed for CHS joints, to calculate the resistance of CFST joints.

314 薄肉ウェブ構造はすば歯車の歯元応力と伝達トルクに及ぼすねじれ角の影響

314 薄肉ウェブ構造はすば歯車の歯元応力と伝達トルクに及ぼすねじれ角の影響

S112013 薄肉ウェブ構造はすば歯車の歯元応力と曲げ疲労強度に及ぼすリム・ウェブ厚さおよびウェブ構造の影響([S112-01]伝動装置の基礎と応用(1))

S112013 薄肉ウェブ構造はすば歯車の歯元応力と曲げ疲労強度に及ぼすリム・ウェブ厚さおよびウェブ構造の影響([S112-01]伝動装置の基礎と応用(1))

S111022 薄肉ウェブ構造はすば歯車の歯元応力に及ぼすねじれ角およびウェブ構造の影響([S111-02]第19回卒業研究コンテスト(2))

Root stresses of thin-rimmed helical gears with symmetric and asymmetric web arrangement of helix angle β_0=10°and 20°, which were meshed with solid helical gear, were measured from the beginning of engagement to the end of the engagement by using the strain gauge method. The changes of root stresses from the beginning of engagement to the end of engagement were examined. The effects of helix angle, rim thickness, web thickness and web structure on the root stresses, the maximum root stress and the meshing position, where the maximum root stress (worst loading position) occurs, were clarified. Furthermore, the obtained results were compared with the results of the solid helical gear.

Effects of Rim and Web Thicknesses on Root Stresses of Thin-Rimmed Helical Gear

This paper presents a study on root stresses of thin-rimmed helical gears with web arrangement of various rim and web thickness. Thin-rimmed helical gears used in this study were meshed with solid helical gear. Root stresses were measured from the beginning of engagement to the end of engagement by using the strain gauge method. The changes of root stresses from the beginning of engagement to the end of engagement were examined and the meshing position where the maximum root stress occurred (worst loading position) was determined. Effects of rim and web thickness on the root stress, the maximum root stress and the position of maximum root stress were clarified.

2102 薄肉対称ウェブ構造はすば歯車の歯元応力と曲げ疲労強度に及ぼすリム・ウェブ厚さの影響(歯車の疲労強度,一般講演)

This paper presents a study on effects of rim and web thickness on root stresses and bending fatigue strength of thin-rimmed helical gears with symmetric web arrangement of various rim and web thickness. Measurement of root stresses and bending fatigue test were carried out for thin-rimmed helical gears with symmetric web arrangement of various rim and web thickness. The changes of the root stresses from the beginning of engagement to the end of engagement, the meshing position (worst loading position), where the maximum root stress occurred, the effects of rim and web thickness on bending fatigue strength and bending fatigue cracks were clarified. Furthermore, the results obtained were compared with the solid helical gear results.

Effects of Rim and Web Thicknesses on Root Stresses of Thin-Rimmed Helical Gears

This paper presents a study on effects of rim and web thicknesses on root stresses of thin-rimmed helical gears. Root stresses of thin-rimmed helical gears with symmetric web arrangement of various rim and web thicknesses, which were meshed with the solid helical gear, were measured from the beginning of engagement to the end of the engagement by the strain gauge method. The changes of the root stress from the beginning of engagement to the end of engagement were examined for the thin-rimmed helical gear with symmetric web arrangement. The meshing position (worst loading position), where the maximum root stress occurred, was determined for the thin-rimmed helical gear with symmetric web arrangement. The effects of rim and web thicknesses on the root stress, the maximum root stress and the position of the maximum root stress were clarified.

501 薄肉非対称ウェブ構造はすば歯車の歯元応力に及ぼすかみ合い歯面の影響(機素潤滑設計I)

501 薄肉非対称ウェブ構造はすば歯車の歯元応力に及ぼすかみ合い歯面の影響(機素潤滑設計I)

917 薄肉対称ウェブ構造はすば歯車の歯元応力(模索潤滑設計III)

917 薄肉対称ウェブ構造はすば歯車の歯元応力(模索潤滑設計III)

912 浸炭および高周波焼入れ薄肉非対称ウェブ構造平歯車の曲げ疲労強度・き裂(機素潤滑設計III)

912 浸炭および高周波焼入れ薄肉非対称ウェブ構造平歯車の曲げ疲労強度・き裂(機素潤滑設計III)

2210 浸炭焼入れ薄肉ウェブ構造歯車の残留応力と曲げ疲労強度(OS1-8 強度(3))

2210 浸炭焼入れ薄肉ウェブ構造歯車の残留応力と曲げ疲労強度(OS1-8 強度(3))

914 浸炭焼入れ薄肉非対称ウェブ構造平歯車の曲げ疲労強度(機素潤滑設計III)

914 浸炭焼入れ薄肉非対称ウェブ構造平歯車の曲げ疲労強度(機素潤滑設計III)

浸炭焼入れ薄肉対称ウェブ構造平歯車の残留応力と曲げ疲労強度に及ぼす浸炭部の影響(O.S.02-1 歯車の強度(1))

This paper presents a study on effects of case-carburized parts on residual stress and bending fatigue strength of case-carburized thin-rimmed spur gears with symmetric web arrangement. A heat conduction analysis and an elastic-plastic stress analysis during the case-carburizing process were carried out for various case-carburizing conditions by the three dimensional finite-element method (3D-FEM), considering changes of the thermal expansion coefficient and the yield stress with the temperature, and then residual stresses were obtained. Bending fatigue tests were carried out for different case-carburized thin-rimmed spur gears with symmetric web arrangement. Effects of case-carburized parts on the residual stress and the bending fatigue strength were examined. These results were also compared with those of solid gears.

802 浸炭焼入れ薄肉対称ウェブ構造歯車の残留応力に及ぼす浸炭部の影響

802 浸炭焼入れ薄肉対称ウェブ構造歯車の残留応力に及ぼす浸炭部の影響

110 浸炭焼入れ薄肉非対称ウェブ構造歯車の残留応力に及ぼす浸炭部の影響

This paper presents a study on effects of carburized parts on residual stresses of case-hardened thin-rimmed spur gears with asymmetric web arrangements. A heat conduction analysis and an elastic-plastic stress analysis during the case-hardening process of thin-rimmed spur gears with asymmetric web arrangements were carried out of various case-hardening conditions by the three-dimensional finite-element method (3D-FEM), and then residual stresses were obtained. The effects of the case depth, the carburized parts (tooth surface, gear-side, rim, web surface), the web structure, the rim thickness on the residual stress were determined.

Root Stresses of Thin-Rimmed Spur Internal Gears of Higher Pressure Angle with Asymmetric Web Arrangemcnts.

This paper presents a study on root stresses of thin-rimmed spur internal gears of higher pressure angle (α0=27°, α0: standard pressure angle) with asymmetric web arrangements for planetary gear units of automatic transmissions of automobiles, caterpillar drives of construction machinery and so on. Tooth deflections of thin-rimmed spur internal gears with asymmetric web arrangements due to a concentrated load in the normal direction of the tooth surface were calculated by the three-dimensional finite-element method (3 D-FEM). On the basis of the calculated results, approximate equations for the influence function of tooth deflection were derived. The load sharing factor and the load distributions on contact lines were calculated using the approximate equations and Kubo and Umezawa's method. Root stresses of thin-rimmed spur internal gear pairs in mesh were calculated by means of 3 D-FEM, and the maximum root stress and its position were examined. Root stresses of the thin-rimmed spur internal gear of higher pressure angle with asymmetric web arrangements were determined by being compared with those of thick-rimmed or solid internal gears and with those of thin-rimmed spur internal gears of α0=20° with asymmetric web arrangements.