Mechanical properties of vinylester resins exposed to marine environments

2013 ◽  
Vol 53 (11) ◽  
pp. 2413-2421 ◽  
Author(s):  
Alexander M. Figliolini ◽  
Leif A. Carlsson
Keyword(s):  
Mechanical Properties ◽  
Marine Environments ◽  
Vinylester Resins

scholarly journals Effects of moisture absorption on damage progression and strength of unidirectional and cross-ply fiberglass–epoxy composites

2018 ◽  
Vol 3 (1) ◽  
pp. 427-438
Author(s):  
Jake D. Nunemaker ◽  
Michael M. Voth ◽  
David A. Miller ◽  
Daniel D. Samborsky ◽  
Paul Murdy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Moisture Absorption ◽  
Fiber Reinforced Polymer ◽  
Material System ◽  
Marine Environments ◽  
Reinforced Polymer ◽  
Damage Progression ◽  
Fiber Reinforced Polymer Composites ◽  
Superior Mechanical Properties ◽  
Marine Hydrokinetic

Abstract. Fiber-reinforced-polymer composites (FRPs) possess superior mechanical properties and formability, making them a desirable material for construction of large optimized mechanical structures, such as aircraft, wind turbines, and marine hydrokinetic (MHK) devices. However, exposure to harsh marine environments can result in moisture absorption into the microstructure of the FRPs comprising these structures and often degrading mechanical properties. Specifically, laminate static and fatigue strengths are often significantly reduced, which must be considered in design of FRP structures in marine environments. A study of fiberglass epoxy unidirectional and cross-ply laminates was conducted to investigate hygrothermal effects on the mechanical behavior of a common material system used in wind applications. Several laminates were aged in 50 ∘C distilled water until maximum saturation was reached. Unconditioned control and the saturated samples were tested in quasi-static tension with the accompaniment of acoustic emission (AE) monitoring. Cross-ply laminates experienced a 54 % reduction in strength due to moisture absorption, while unidirectional laminate strengths were reduced by 40 %. Stress–strain curves and AE activity of the samples were analyzed to identify changes in damage progression due to aging.

Synergistic effects of marine environments and flexural fatigue on carbon fiber–vinyl ester composites protected by gelcoat

2017 ◽  
Vol 51 (26) ◽  
pp. 3711-3717 ◽  
Author(s):  
Arash Afshar
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Vinyl Ester ◽  
Damage Accumulation ◽  
Protective Coatings ◽  
Synergistic Effects ◽  
Digital Microscopy ◽  
Marine Environments ◽  
Coated Carbon

The current process for designing reliable and enduring naval composite crafts and structures is instrumentally dependent upon utilizing protective coatings to shield composite materials against environmental based degradation. However, as coatings can be vulnerable to corrosion and/or erosion in harsh marine environments, they may gradually lose their protective abilities, leading to damage accumulation in the protected composites. To demonstrate the criticality of this process, gel-coated carbon fiber–vinyl ester laminates are subjected to a simulated marine environment consisting of ultraviolet (UV) radiation, moisture, and cyclic mechanical loading. Next, degradation in composite laminates is probed through measuring the flexural strength. Damage in gelcoat is further characterized by digital microscopy of its surface. Correlation between degradation of the gelcoat surface and loss in the mechanical properties of coated composite laminates is also investigated.

scholarly journals Effects of moisture absorption on damage progression and strength of unidirectional and cross-ply fiberglass-epoxy composites

2018 ◽  
Author(s):  
Jake D. Nunemaker ◽  
Michael M. Voth ◽  
David A. Miller ◽  
Daniel D. Samborsky ◽  
Paul Murdy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Moisture Absorption ◽  
Fiber Reinforced Polymer ◽  
Material System ◽  
Marine Environments ◽  
Fiber Glass ◽  
Reinforced Polymer ◽  
Damage Progression ◽  
Fiber Reinforced Polymer Composites ◽  
Superior Mechanical Properties

Abstract. Fiber-Reinforced-Polymer composites (FRP's) possess superior mechanical properties and formability, making them a desirable material for construction of large optimized mechanical structures, such as aircraft, wind turbines, and marine hydro kinetic (MHK) devices. However, exposure to harsh marine environments can result in moisture absorption into the microstructure of the FRP's comprising these structures and often degrading mechanical properties. Specifically, laminate static and fatigue strengths are often significantly reduced, which must be considered in design of FRP structures in marine environments. A study of fiber-glass epoxy unidirectional and cross-ply laminates was conducted to investigate hygrothermal effects on the mechanical behavior of a common material system used in wind applications. Several laminates were aged in 50 °C distilled water until maximum saturation was reached. Unconditioned control and the saturated samples were tested in quasi-static tension with the accompaniment of Acoustic Emission (AE) monitoring. Cross-ply laminates experienced 54 % reduction in strengths from due to moisture absorption, while unidirectional laminates strengths were reduced by 40 %. Stress-strain curves and AE activity of the samples were analyzed to identify changes in damage progression due to aging.

Mechanical properties of carbon fiber/vinylester composites exposed to marine environments

2013 ◽  
Vol 35 (8) ◽  
pp. 1559-1569 ◽  
Author(s):  
Alexander M. Figliolini ◽  
Leif A. Carlsson
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Marine Environments

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

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