scholarly journals Thermoplastic Composites for Integrally Woven Pressure Actuated Cellular Structures: Design Approach and Material Investigation

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3128
Author(s):  
Michael Vorhof ◽  
Cornelia Sennewald ◽  
Philipp Schegner ◽  
Patrick Meyer ◽  
Christian Hühne ◽  
...  
Keyword(s):  
Compliant Mechanisms ◽  
Thermoplastic Composites ◽  
Cellular Structures ◽  
Experimental Investigations ◽  
Deformation Capacity ◽  
High Deformation Rate ◽  
Double Row ◽  
High Deformation ◽  
Textile Preform ◽  
Further Development

The use of pressure-actuated cellular structures (PACS) is an effective approach for the application of compliant mechanisms. Analogous to the model in nature, the Venus flytrap, they are made of discrete pressure-activated rows and can be deformed with high stiffness at a high deformation rate. In previous work, a new innovative approach in their integral textile-based manufacturing has been demonstrated based on the weaving technique. In this work, the theoretical and experimental work on the further development of PACS from simple single-row to double-row PACS with antagonistic deformation capability is presented. Supported by experimental investigations, the necessary adaptations in the design of the textile preform and the polymer composite design are presented and concretized. Based on the results of pre-simulations of the deformation capacity of the new PACS, their performance was evaluated, the results of which are presented.

scholarly journals Additive Manufacturing-Based In Situ Consolidation of Continuous Carbon Fibre-Reinforced Polycarbonate

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2450
Author(s):  
Andreas Borowski ◽  
Christian Vogel ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Maik Gude ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Carbon Fibre ◽  
Bending Test ◽  
Thermoplastic Composites ◽  
Experimental Investigations ◽  
Material Structure ◽  
Three Point Bending ◽  
Continuous Fibre ◽  
Local Material

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.

scholarly journals Comparative Analysis of the Energy Dissipation of Steel Buildings with Concentric and Eccentric Braces

2015 ◽  
Vol 9 (1) ◽  
pp. 295-307 ◽  
Author(s):  
Edelis del V. Marquez A. ◽  
William Lobo-Q ◽  
Juan C. Vielma
Keyword(s):  
Energy Dissipation ◽  
Shear Failure ◽  
Numerical Models ◽  
Deformation Energy ◽  
Seismic Zone ◽  
Deformation Capacity ◽  
Building Structures ◽  
Steel Buildings ◽  
High Deformation ◽  
Energy Dissipation Capacity

A comparative study has been done to analyze the behavior of regular steel building structures of 4, 6, 8 and 10 stories, located in seismic zone 5 and soil type S1. The structures were upgraded with different brace configurations according to current Venezuelan codes. A total number of 24 numerical models were analyzed considering non-linear static and incremental dynamic analysis (IDA). The buildings were initially designed as moment resisting frames, and upgraded with six different bracing configurations: concentric braces in “X” and inverted “V”; eccentric braces inverted "V" with horizontal links, inverted “Y” and “X” with vertical links. Short length links were used to ensure a shear failure. The used methodology is based on obtaining the capacity, IDA curves, and bilinear approximations of these curves that allow the determination of yield and ultimate capacity points, in order to estimate important parameters of seismic response: overstrength and ductility; and considering these areas under the curves to estimate elastic deformation energy, energy dissipated by hysteretic damping and equivalent damping. According to the results, the cases with no brace enhancement showed the lowest lateral strength and lateral stiffness and high deformation capacity. On the other hand, the concentric bracing cases, resulted with the highest stiffness and strength and the lowest deformation capacity, therefore they have low ductility and energy dissipation capacity under seismic loading. Structures with links showed intermediate stiffness and strengths, resulting in the best performance in terms of ductility and energy dissipation capacity. The present study provides a better understanding of the benefits of eccentrically braced systems.

Development of Rolled Product Manufacturing Technology for Pipes with High Deformation Capacity

Metallurgist ◽  
2020 ◽  
Vol 63 (11-12) ◽  
pp. 1204-1219
Author(s):  
A. M. Barykov ◽  
P. P. Stepanov ◽  
V. I. Il’inskii ◽  
S. V. Golovin ◽  
A. V. Chervonnyi ◽  
...  
Keyword(s):  
Rolled Product ◽  
Manufacturing Technology ◽  
Deformation Capacity ◽  
High Deformation ◽  
Product Manufacturing

Investigating the confining compressibility of STF at high deformation rate

2012 ◽  
Vol 60 (3) ◽  
pp. 31101 ◽  
Author(s):  
Weifeng Jiang ◽  
Xinglong Gong ◽  
Yulei Xu ◽  
Shouhu Xuan ◽  
Wanquan Jiang ◽  
...  
Keyword(s):  
Deformation Rate ◽  
High Deformation Rate ◽  
High Deformation

scholarly journals Effect of Hot Deformation Temperature on Texture Formation Regularity of CGO Silicon Steel under High Deformation Rate

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Zhi-chao Li ◽  
Ning Dang ◽  
Zhen-li Mi
Keyword(s):  
Hot Deformation ◽  
Deformation Rate ◽  
Deformation Temperature ◽  
Room Temperature ◽  
Silicon Steel ◽  
High Deformation Rate ◽  
Goss Texture ◽  
High Deformation ◽  
Increasing Trend ◽  
Pearlite Content

The influence of hot deformation temperature on microstructure and texture of CGO silicon steel under the condition of a high deformation rate (100 s-1) was studied by SEM and EBSD techniques. The results indicate that the typical microstructures at room temperature consist of ferrite and pearlite under different hot deformation temperatures. The higher deformation temperature is beneficial to obtain a more uniform recrystallization microstructure and lower pearlite content. Cubic texture{100}001and rotated cubic texture{100}011are dominant texture components in the tested steels, and{111}112texture inγfiber is also strong, the intensity of which is higher than that of{111}110texture. Goss texture{110}001is weak. With the rising of the hot deformation temperature,{100}011texture decreases firstly and then increases at 1100°C. When the hot deformation temperature raises from 800°C to 900°C,{111}112texture shows an increasing trend, while{111}110texture content is stable. When the temperature further increases to 1100°C and 1150°C,{111}112and{111}110textures are slightly weakened.

Rheology of Dilute Polymer Solutions and Engine Lubricants in High Deformation Rate Extensional Flows Produced by Bubble Collapse

2004 ◽  
Vol 126 (2) ◽  
pp. 162-169 ◽  
Author(s):  
M. S. Barrow ◽  
S. W. J. Brown ◽  
S. Cordy ◽  
P. R. Williams ◽  
R. L. Williams
Keyword(s):  
Xanthan Gum ◽  
Extensional Flow ◽  
Journal Bearings ◽  
Bubble Collapse ◽  
Liquid Jets ◽  
Pressure Waves ◽  
Polymeric Additive ◽  
High Deformation Rate ◽  
High Deformation ◽  
Dilute Polymer Solutions

We report a study of liquid jets formed by the collapse of bubbles under cavitation-generated pressure waves. Such jets involve an extensional flow which is characterized by high rates of extension, the latter being relevant to considerations of the flow of oils within dynamically loaded journal bearings. The technique reported here is found to be sensitive to the influence of extremely small concentrations of high molecular weight polymeric additive (xanthan gum). Commercial multigrade oils are also found to exhibit significantly larger resistance to extensional flow than their Newtonian counterparts and, insofar as the multigrade oils studied here are made viscoelastic by polymer additives, and possess significant levels of resistance to extension, the results provide evidence in support of a mitigating effect of viscoelasticity on cavitation, as mooted by Berker et al. [3].

Rheology of Multigrade Engine Lubricants in High Deformation Rate Extensional Flow

2003 ◽  
Author(s):  
S. Cordy ◽  
M. S. Barrow ◽  
S. W. J. Brown ◽  
K. Hawkins ◽  
P. R. Williams
Keyword(s):  
Deformation Rate ◽  
Extensional Flow ◽  
High Deformation Rate ◽  
High Deformation

Stress Relief in Contact-Aided Cellular Compliant Mechanisms

2008 ◽  
Author(s):  
Vipul Mehta ◽  
Mary Frecker ◽  
George Lesieutre
Keyword(s):  
Compliant Mechanisms ◽  
High Strain ◽  
Stress Relief ◽  
Cellular Structures ◽  
Morphing Aircraft ◽  
Fracture Failure ◽  
Global Strain ◽  
Aircraft Skin ◽  
Structural Mass ◽  
Contact Mechanism

Cellular structures with an internal contact-mechanism are investigated. These contact-aided compliant mechanisms are shown to reduce the local tensile stresses, thereby providing additional global strain before yielding or fracture failure compared to honeycomb or auxetic cellular structures. An analytical model for such structures is developed and it is validated using FEA simulations. Two different materials are considered for comparison. More than 100% improvement in global strain capability is possible using the contact. A high-strain morphing aircraft skin is examined as an application of these mechanisms. The contact-aided cellular compliant mechanisms are more advantageous in terms of both the structural mass as well as the global strain compared to a non-contact design. In the application considered the stress-relief mechanism increased the global strain capability by as high as 37%.

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