Flexural creep tests and long-term mechanical behavior of fiber-reinforced polymeric composite tubes

2018 ◽  
Vol 193 ◽  
pp. 154-164 ◽  
Author(s):  
Zengqin Yang ◽  
Hui Wang ◽  
Xiaofei Ma ◽  
Fulin Shang ◽  
Yu Ma ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Polymeric Composite ◽  
Fiber Reinforced ◽  
Creep Tests ◽  
Composite Tubes ◽  
Flexural Creep

Lifetime prediction of high-modulus polyethylene yarns subjected to creep using the Larson–Miller methodology

2019 ◽  
Vol 27 (7) ◽  
pp. 400-406
Author(s):  
Jefferson Morais Gautério ◽  
Leonardo Cofferri ◽  
Antonio Henrique Monteiro da Fonsec da Silva ◽  
Felipe Tempel Stumpf
Keyword(s):  
High Temperature ◽  
Mechanical Behavior ◽  
Polymeric Materials ◽  
Constant Load ◽  
Lifetime Prediction ◽  
High Modulus ◽  
Accelerated Tests ◽  
Creep Tests ◽  
Modulus Polyethylene

The aim of the present work is to apply the Larson–Miller technique for the study of the mechanical behavior under creep of high-modulus polyethylene (HMPE) fibers focused on use as in offshore mooring ropes. Creep is known to be a long-term phenomenon, so in most cases, reproducing such experiments in real time is not feasible, and as the life span of anchoring systems must be in the order of decades, accelerated tests are required to verify the long-term mechanical behavior of the material. The methodology using the Larson–Miller parameter is a well-documented and powerful technique for materials’ lifetime prediction, although seldom applied to polymeric materials. It involves in performing accelerated (high temperature and/or loads) creep tests to determine the parameters that are later used to estimate the rupture time of the material under constant load. It is concluded that the Larson–Miller technique is efficient for calculating the lifetime of HMPE subjected to creep.

On the Design and Analysis of Fiber Reinforced Polymeric Composite Pipes and Vessels

2002 ◽  
Author(s):  
Fernand Ellyin
Keyword(s):  
Failure Modes ◽  
Polymeric Composite ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Frp Composites ◽  
Reinforced Plastic ◽  
Optimum Placement ◽  
Composite Pipes ◽  
Multiaxial Loadings

Fiber reinforced plastic (FRP) composites offer a number of advantages over the conventional industrial materials. The reluctance of adopting composite materials in high pressure applications, is partly due to a limited understanding of their behavior under multiaxial loadings and lack of qualified design methodologies. Design and analysis issues concerning pressurized components made of fiber reinforced plastic composites, are discussed in this paper. Specifically, the optimum placement of reinforcement with respect to the applied loads, failure modes and failure analysis techniques, and a method of design based on long-term leakage envelope, are presented.

Physical Aging in Long Term Creep of Polymeric Composite Laminates

2007 ◽  
Vol 23 (3) ◽  
pp. 245-252 ◽  
Author(s):  
H. W. Hu
Keyword(s):  
Aging Time ◽  
Composite Laminates ◽  
Physical Aging ◽  
Creep Compliance ◽  
Polymeric Composite ◽  
Reference Curve ◽  
Creep Tests ◽  
Time Model ◽  
Term Creep

AbstractThis paper presents a complete approach to characterize physical aging in long term creep of composite laminates using short term creep test. Carbon/epoxy composite IM7/977−3 was use to make the coupon specimens of unidirectional fiber orientation and symmetrical laminates. Creep tests were conducted on the specimens to obtain momentary compliances at isothermal conditions. Physical aging in elastic and in creep compliances were modeled respectively. Momentary creep compliances in various aging times were shifted to superpose a reference curve by introducing shift factors for both relaxation time and shape factor of a power law model. Linear relations between shift factors and aging time in log-log scale were found and defined as shift rates. By using reference curve associated with the shift rates, momentary creep compliance in any given aging time can be predicted. By introducing a time dependent shift factor, momentary creep compliance can be modified and turned into an effective time model, which can successfully predict the long term creep of composite laminates at isothermal aging. This approach only requires the test data of momentary creep, and no material properties in each lamina are needed.

Influence of hydrostatic pressure and volumetric strain on the mechanical long term behavior of polymers

2012 ◽  
Vol 32 (6-7) ◽  
pp. 327-333 ◽  
Author(s):  
Tobias Naumann ◽  
Markus Stommel
Keyword(s):  
Hydrostatic Pressure ◽  
Mechanical Behavior ◽  
Free Volume ◽  
Creep Behavior ◽  
Volumetric Strain ◽  
Material Model ◽  
Tensile Creep ◽  
Creep Tests ◽  
Long Term Behavior

Abstract One of the most crucial issues in developing a material model to describe the long term behaviour of polymers is to represent adequately the load dependency of the considered material. In many publications, it is shown that the free volume affects the mechanical behavior of polymers. For a further investigation of the dependency of the creep behavior on free volume, different experiments are presented in this paper. In one experiment, the creep behavior under tension and shear are compared, to see how the different hydrostatic pressures in these tests influence mechanical behavior. Furthermore, tensile creep tests under different hydrostatic pressures are conducted experimentally. The experiments are conducted on a polycarbonate, a polypropylene and a polymethyl methacrylate. It is shown that the hydrostatic pressure has a significant influence on the creep behavior of all three materials. This effect is related to the change of free volume.

Effects of high pressure on the crystallization of carbon fiber reinforced polyetheretherketone (CF/PEEK) laminate composites

1990 ◽  
Vol 48 (4) ◽  
pp. 876-877
Author(s):  
Hong-Ming Lin ◽  
C. H. Liu ◽  
R. F. Lee
Keyword(s):  
High Pressure ◽  
Carbon Fiber ◽  
Sample Surface ◽  
High Yield ◽  
Fiber Reinforced ◽  
Laminate Composites ◽  
Peek Composite ◽  
Continuous Carbon Fiber ◽  
Carbon Fiber Reinforced

Polyetheretherketone (PEEK) is a crystallizable thermoplastic used as composite matrix materials in application which requires high yield stress, high toughness, long term high temperature service, and resistance to solvent and radiation. There have been several reports on the crystallization behavior of neat PEEK and of CF/PEEK composite. Other reports discussed the effects of crystallization on the mechanical properties of PEEK and CF/PEEK composites. However, these reports were all concerned with the crystallization or melting processes at or close to atmospheric pressure. Thus, the effects of high pressure on the crystallization of CF/PEEK will be examined in this study.The continuous carbon fiber reinforced PEEK (CF/PEEK) laminate composite with 68 wt.% of fibers was obtained from Imperial Chemical Industry (ICI). For the high pressure experiments, HIP was used to keep these samples under 1000, 1500 or 2000 atm. Then the samples were slowly cooled from 420 °C to 60 °C in the cooling rate about 1 - 2 degree per minute to induce high pressure crystallization. After the high pressure treatment, the samples were scanned in regular DSC to study the crystallinity and the melting temperature. Following the regular polishing, etching, and gold coating of the sample surface, the scanning electron microscope (SEM) was used to image the microstructure of the crystals. Also the samples about 25mmx5mmx3mm were prepared for the 3-point bending tests.

Effect of long climatic ageing on the microstructure of the surface of сarbon-fiber-reinforced plastics on base epoxy matrix

2019 ◽  
pp. 157-169 ◽  
Author(s):  
I. S. Deev ◽  
E. V. Kurshev ◽  
S. L. Lonsky
Keyword(s):  
Climatic Factors ◽  
Temperate Climate ◽  
Fiber Reinforced ◽  
Humid Climate ◽  
Climatic Zones ◽  
Reinforced Plastics ◽  
Carbon Plastics ◽  
Fiber Reinforced Plastics ◽  
Determining Factor

Studies and experimental data on the microstructure of the surface of samples of epoxy сarbon-fiber-reinforced plastics that have undergone long-term (up to 5 years) climatic aging in different climatic zones of Russia have been conducted: under conditions of the industrial zone of temperate climate (Moscow, MTsKI); temperate warm climate (Gelendzhik, GTsKI); a warm humid climate (Sochi, GNIP RAS). It is established that the determining factor for aging of carbon plastics is the duration of the complex effect of climatic factors: the longer the period of climatic aging, the more significant changes occur in the microstructure of the surface of the materials. The intensity of the aging process and the degree of microstructural changes in the surface of carbon plastics are affected by the features of the climatic zone. general regularities and features of the destruction of the surface of carbon plastics after a long-term exposure to climatic factors have been established on the basis of the analysis and systematization of the results of microstructural studies.

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