scholarly journals A computational modeling approach based on random fields for short fiber-reinforced composites with experimental verification by nanoindentation and tensile tests

2021 ◽  
Author(s):  
Natalie Rauter
Keyword(s):  
Numerical Simulations ◽  
Correlation Functions ◽  
Material Properties ◽  
Random Fields ◽  
Tensile Tests ◽  
Short Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Component Level

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.

scholarly journals Experimental Characterization of Short Fiber-Reinforced Composites on the Mesoscale by Indentation Tests

2021 ◽  
Author(s):  
Natalie Rauter ◽  
Rolf Lammering
Keyword(s):  
Young’S Modulus ◽  
Material Properties ◽  
Young's Modulus ◽  
Short Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Indentation Tests ◽  
Fiber Reinforced Material

AbstractIndentation tests are widely used to characterize the material properties of heterogeneous materials. So far there is no explicit analysis of the spatially distributed material properties for short fiber-reinforced composites on the mesoscale as well as a determination of the effective cross-section that is characterized by the obtained measurement results. Hence, the primary objective of this study is the characterization of short fiber-reinforced composites on the mesoscale. Furthermore, it is of interest to determine the corresponding area for which the obtained material parameters are valid. For the experimental investigation of local material properties of short fiber-reinforced composites, the Young’s modulus is obtained by indentation tests. The measured values of the Young’s modulus are compared to results gained by numerical simulation. The numerical model represents an actual microstructure derived from a micrograph of the used material. The analysis of the short fiber-reinforced material by indentation tests reveals the layered structure of the specimen induced by the injection molding process and the oriented material properties of the reinforced material are observed. In addition, the experimentally obtained values for Young’s modulus meet the results of a corresponding numerical analysis. Finally, it is shown, that the area characterized by the indentation test is 25 times larger than the actual projected area of the indentation tip. This leads to the conclusion that indentation tests are an appropriate tool to characterize short fiber-reinforced material on the mesoscale.

Anisotropic Effective Moduli of Cracked Short-Fiber Reinforced Composites

1999 ◽  
Vol 66 (3) ◽  
pp. 709-713 ◽  
Author(s):  
R. S. Feltman ◽  
M. H. Santare
Keyword(s):  
Short Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Effective Moduli ◽  
Fiber Reinforced ◽  
Fiber Fracture ◽  
Composite Systems ◽  
Reinforced Composite ◽  
Anisotropic Elastic ◽  
Energy Dissipated

A model is presented to analyze the effect of fiber fracture on the anisotropic elastic properties of short-fiber reinforced composite materials. The effective moduli of the material are modeled using a self-consistent scheme which includes the calculated energy dissipated through the opening of a crack in an arbitrarily oriented elliptical inclusion. The model is an extension of previous works which have modeled isotropic properties of short-fiber reinforced composites with fiber breakage and anisotropic properties of monolithic materials with microcracks. Two-dimensional planar composite systems are considered. The model allows for the calculation of moduli under varying degrees of fiber alignment and damage orientation. In the results, both aligned fiber systems and randomly oriented fiber systems with damage-induced anisotropy are examined.

scholarly journals Multiscale thermomechanical modeling of short fiber-reinforced composites

2017 ◽  
Vol 24 (5) ◽  
pp. 765-772 ◽  
Author(s):  
Dawei Jia ◽  
Huiji Shi ◽  
Lei Cheng
Keyword(s):  
Thermal Loading ◽  
Volume Fraction ◽  
Numerical Procedure ◽  
Thermal Conditions ◽  
Cyclic Hardening ◽  
Short Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Thermomechanical Modeling

AbstractA study of the micromechanical behavior to predict the overall response of short fiber-reinforced composites under cyclic mechanical and thermal loading is presented. The instantaneous average over a “representative volume” of the material is considered. The influence of the short fiber’s aspect ratio, volume fraction, and spatial orientation has been investigated. The linear combined hardening model is used to describe the cyclic hardening effects in the case of metal matrix. A numerical procedure is used to predict the response of composites under mechanical and thermal conditions. The results of the numerical procedure have been compared to the results of three different models and to published experimental data.

scholarly journals Applying ASTM Standards to Tensile Tests of Musculoskeletal Soft Tissue: Methods to Reduce Grip Failures and Promote Reproducibility

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Madison E. Wale ◽  
Derek Q. Nesbitt ◽  
Bradley S. Henderson ◽  
Clare K. Fitzpatrick ◽  
Jaremy J. Creechley ◽  
...  
Keyword(s):  
Tensile Testing ◽  
Soft Tissues ◽  
Tensile Tests ◽  
Standard Test ◽  
International Standards ◽  
Fiber Reinforced Composites ◽  
Fiber Direction ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Test Standards

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.

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