The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks（ANN）. Herein hard rock brittleness is defined using Yagiz＇method. A pre...The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks（ANN）. Herein hard rock brittleness is defined using Yagiz＇method. A predictive model is developed using a comprehensive database compiled from 30 years＇ worth of rock tests at the Earth Mechanics Institute（EMI）, Colorado School of Mines. The model is sensitive to density, elastic properties, and P- and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and multiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.展开更多
In France,the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector,thanks to their good physicochemical properties,environmental reasons,health neutrality and du...In France,the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector,thanks to their good physicochemical properties,environmental reasons,health neutrality and due to the European Council Directives on the reuse,recycling and valorization of car components and materials.The aim of our study is to investigate biochemical,physicochemical,and mechanical properties of technical flax fibers to evaluate the impact of transformation processes(scutching,hackling,and homogenization)on final properties of associated composite materials.Different chemical analysis such as Van Soest(biochemical fraction measurement),FTIR(Fourier Transform InfraRed spectroscopy),and XRD(X-ray diffraction)were carried out on different process modalities and show that there is no significant difference in terms of biochemical fraction and crystallinity index.By the same token,mechanical behavior shows that Young’s modulus is not affected by the transformation process.This result is also observed for thermal behavior.The results highlight the fact that the transformation processes of technical fibers do not really affect their physicochemical and mechanical performances.展开更多
文摘The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks（ANN）. Herein hard rock brittleness is defined using Yagiz＇method. A predictive model is developed using a comprehensive database compiled from 30 years＇ worth of rock tests at the Earth Mechanics Institute（EMI）, Colorado School of Mines. The model is sensitive to density, elastic properties, and P- and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and multiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.
基金funded by FEDER and it was carried out in collaboration with LSM and LINEO Company.
文摘In France,the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector,thanks to their good physicochemical properties,environmental reasons,health neutrality and due to the European Council Directives on the reuse,recycling and valorization of car components and materials.The aim of our study is to investigate biochemical,physicochemical,and mechanical properties of technical flax fibers to evaluate the impact of transformation processes(scutching,hackling,and homogenization)on final properties of associated composite materials.Different chemical analysis such as Van Soest(biochemical fraction measurement),FTIR(Fourier Transform InfraRed spectroscopy),and XRD(X-ray diffraction)were carried out on different process modalities and show that there is no significant difference in terms of biochemical fraction and crystallinity index.By the same token,mechanical behavior shows that Young’s modulus is not affected by the transformation process.This result is also observed for thermal behavior.The results highlight the fact that the transformation processes of technical fibers do not really affect their physicochemical and mechanical performances.
