scholarly journals Mechanical Microstructure Characterization of Discontinuous‐Fiber Reinforced Composites by means of Experimental‐Numerical Micro Tensile Tests

PAMM ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Michael Schober ◽  
Kerstin Dittmann ◽  
Peter Gumbsch ◽  
Takashi Kuboki ◽  
Jörg Hohe
Author(s):  
Natalie Rauter

AbstractIn this study a modeling approach for short fiber-reinforced composites is presented which allows one to consider information from the microstructure of the compound while modeling on the component level. The proposed technique is based on the determination of correlation functions by the moving window method. Using these correlation functions random fields are generated by the Karhunen–Loève expansion. Linear elastic numerical simulations are conducted on the mesoscale and component level based on the probabilistic characteristics of the microstructure derived from a two-dimensional micrograph. The experimental validation by nanoindentation on the mesoscale shows good conformity with the numerical simulations. For the numerical modeling on the component level the comparison of experimentally obtained Young’s modulus by tensile tests with numerical simulations indicate that the presented approach requires three-dimensional information of the probabilistic characteristics of the microstructure. Using this information not only the overall material properties are approximated sufficiently, but also the local distribution of the material properties shows the same trend as the results of conducted tensile tests.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Madison E. Wale ◽  
Derek Q. Nesbitt ◽  
Bradley S. Henderson ◽  
Clare K. Fitzpatrick ◽  
Jaremy J. Creechley ◽  
...  

Abstract Tensile testing is an essential experiment to assess the mechanical integrity of musculoskeletal soft tissues, yet standard test methods have not been developed to ensure the quality and reproducibility of these experiments. The ASTM International standards organization has created tensile test standards for common industry materials that specify geometric dimensions of test specimens (coupons) that promote valid failures within the gage section (midsubstance), away from the grips. This study examined whether ASTM test standards for plastics, elastomers, and fiber-reinforced composites are suitable for tensile testing of bovine meniscus along the circumferential fiber direction. We found that dumbbell (DB) shaped coupons based on ASTM standards for elastomers and plastics had an 80% and 60% rate of midsubstance failures, respectively. The rate of midsubstance failures dropped to 20% when using straight (ST) coupons based on ASTM standards for fiber-reinforced composites. The mechanical properties of dumbbell shaped coupons were also significantly greater than straight coupons. Finite element models of the test coupons revealed stress distributions that supported our experimental findings. In addition, we found that a commercial deli-slicer was able to slice meniscus to uniform layer thicknesses that were within ASTM dimensional tolerances. This study provides methods, recommendations, and insights that can advance the standardization of tensile testing in meniscus and other soft fibrous tissues.


2002 ◽  
Vol 74 (4) ◽  
pp. 601-628 ◽  
Author(s):  
D. R. Moore ◽  
A. J. Cervenka

Characterization of continuous fiber-reinforced composites is examined in terms of processing, properties, and structure. Five processing and five property topics are then examined in terms of reviewing some of the historic background in these areas with the aim of identifying current issues and requirements for the future. The topics covered in the processing section are: polymeric matrix, impregnation, interfacial effects, residual stresses, and pre-preg tack. In the mechanical properties section the topics are: choice of standard, recycling and reusability, durability, environmental strength, and toughness. The paper provides a ten-point plan for future requirements.


Sign in / Sign up

Export Citation Format

Share Document