Durability and Damage Tolerance of a Polyimide Chopped Fiber Composite Subjected to Thermomechanical Fatigue Missions and Creep Loadings

2008 ◽  
pp. 285-285-25 ◽  
Author(s):  
MG Castelli ◽  
JK Sutter ◽  
D Benson
Keyword(s):  
Damage Tolerance ◽  
Fiber Composite ◽  
Thermomechanical Fatigue

High Temperature Intermetallic Composites

1988 ◽  
Vol 120 ◽  
Author(s):  
D. L. Anton
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Damage Tolerance ◽  
Fiber Composite ◽  
Transient Liquid Phase ◽  
Plastic Response ◽  
Glass Composites ◽  
Aerospace Applications ◽  
Reinforcing Fiber ◽  
Thermal Stability Of

AbstractMany intermetallic compounds possess properties which make them excellent candidates for high temperature use in advanced gas turbine and aerospace applications. One method proposed for increasing damage tolerance in these brittle materials is to artificially composite them with high temperature fibers as utilized in both ceramic and glass composites. Fabrication of these composites is a formidable problem. One method of fabricating these structures, termed here Transient Liquid Phase Consolidation, TLPC, is demonstrated for a number of intermetallic/reinforcing fiber combinations. Thermal stability of the fibers in the intermetallic matrices was observed with FP Alumina being the most stable. Ambient temperature tensile property evaluations were made on monolithic, chopped and aligned FP fiber reinforced Al3 Ta with the aligned structure having the highest ultimate strength and the chopped fiber composite the greatest pseudo plastic response.

Defect/damage tolerance of pressurized fiber composite shells

2001 ◽  
Vol 51 (2) ◽  
pp. 159-168 ◽  
Author(s):  
Christos C Chamis ◽  
Levon Minnetyan
Keyword(s):  
Damage Tolerance ◽  
Fiber Composite ◽  
Composite Shells

scholarly journals Analysis of the Thermomechanical Fatigue Behavior of Fully Ferritic High Chromium Steel Crofer®22 H with Cyclic Indentation Testing

2020 ◽  
Vol 10 (18) ◽  
pp. 6461 ◽  
Author(s):  
Bastian Blinn ◽  
David Görzen ◽  
Torsten Fischer ◽  
Bernd Kuhn ◽  
Tilmann Beck
Keyword(s):  
Deformation Behavior ◽  
Damage Tolerance ◽  
Fatigue Behavior ◽  
Failure Mechanisms ◽  
Cyclic Hardening ◽  
Thermomechanical Fatigue ◽  
Chromium Steel ◽  
Indentation Tests ◽  
Cyclic Indentation ◽  
Induced Changes

The 22 wt.% Cr, fully ferritic stainless steel Crofer®22 H has higher thermomechanical fatigue (TMF)- lifetime compared to advanced ferritic-martensitic P91, which is assumed to be caused by different damage tolerance, leading to differences in crack propagation and failure mechanisms. To analyze this, instrumented cyclic indentation tests (CITs) were used because the material’s cyclic hardening potential—which strongly correlates with damage tolerance, can be determined by analyzing the deformation behavior in CITs. In the presented work, CITs were performed for both materials at specimens loaded for different numbers of TMF-cycles. These investigations show higher damage tolerance for Crofer®22 H and demonstrate changes in damage tolerance during TMF-loading for both materials, which correlates with the cyclic deformation behavior observed in TMF-tests. Furthermore, the results obtained at Crofer®22 H indicate an increase of damage tolerance in the second half of TMF-lifetime, which cannot be observed for P91. Moreover, CITs were performed at Crofer®22 H in the vicinity of a fatigue crack, enabling to locally analyze the damage tolerance. These CITs show differences between crack edges and the crack tip. Conclusively, the presented results demonstrate that CITs can be utilized to analyze TMF-induced changes in damage tolerance.

Cytocompatibility of Carbon Nanofiber Materials for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Carbon Fiber ◽  
Surface Energy ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
Carbon Nanofiber ◽  
Fiber Composite ◽  
Scar Tissue ◽  
Pc 12 Cells ◽  
Low Surface Energy ◽  
Poly Carbonate

AbstractSince the cytocompatibility of carbon nanofibers with respect to neural applications remains largely uninvestigated, the objective of the present in vitro study was to determine cytocompatibility properties of formulations containing carbon nanofibers. Carbon fiber substrates were prepared from four different types of carbon fibers, two with nanoscale diameters (nanophase, or less than or equal to 100 nm) and two with conventional diameters (or greater than 200 nm). Within these two categories, both a high and a low surface energy fiber were investigated and tested. Astrocytes (glial scar tissue-forming cells) and pheochromocytoma cells (PC-12; neuronal-like cells) were seeded separately onto the substrates. Results provided the first evidence that astrocytes preferentially adhered on the carbon fiber that had the largest diameter and the lowest surface energy. PC-12 cells exhibited the most neurites on the carbon fiber with nanodimensions and low surface energy. These results may indicate that PC-12 cells prefer nanoscale carbon fibers while astrocytes prefer conventional scale fibers. A composite was formed from poly-carbonate urethane and the 60 nm carbon fiber. Composite substrates were thus formed using different weight percentages of this fiber in the polymer matrix. Increased astrocyte adherence and PC-12 neurite density corresponded to decreasing amounts of the carbon nanofibers in the poly-carbonate urethane matrices. Controlling carbon fiber diameter may be an approach for increasing implant contact with neurons and decreasing scar tissue formation.

Modeling of Strain Energy Harvesting in Pneumatic Tires Using Piezoelectric Transducer

2014 ◽  
Vol 42 (1) ◽  
pp. 16-34 ◽  
Author(s):  
Ali E. Kubba ◽  
Mohammad Behroozi ◽  
Oluremi A. Olatunbosun ◽  
Carl Anthony ◽  
Kyle Jiang
Keyword(s):  
Energy Harvesting ◽  
Strain Energy ◽  
Fiber Composite ◽  
Experimental Tests ◽  
Evaluation Study ◽  
Monitoring Systems ◽  
Monitoring Device ◽  
Optimum Location ◽  
Piezoelectric Fiber Composite ◽  
Piezoelectric Fiber

ABSTRACT This paper presents an evaluation study of the feasibility of harvesting energy from rolling tire deformation and using it to supply a tire monitoring device installed within the tire cavity. The developed technique is simulated by using a flexible piezoelectric fiber composite transducer (PFC) adhered onto the tire inner liner acting as the energy harvesting element for tire monitoring systems. The PFC element generates electric charge when strain is applied to it. Tire cyclic deformation, particularly at the contact patch surface due to rolling conditions, can be exploited to harvest energy. Finite element simulations, using Abaqus package, were employed to estimate the available strain energy within the tire structure in order to select the optimum location for the PFC element. Experimental tests were carried out by using an evaluation kit for the energy harvesting element installed within the tire cavity to examine the PFC performance under controlled speed and loading conditions.

Damage tolerance of bismaleimide composites

1988 ◽  
Author(s):  
S. TYAHLA ◽  
H. STORR
Keyword(s):  
Damage Tolerance
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