Experimental Study On The Mechanical Properties Of Caragana Materials And Its Reinforced Composites

Tens of millions of mu of Caragana were planted at Yanmengguan in Shanxi. Caragana has a high nutritional value, strength and hardness. It also has a function of sand fixation. Because of its high fiber strength and tenacity, Caragana can also be the resources of agricultural facilities, agricultural packaging products, absorbent refining products and green building materials. In a word, Caragana has a broad application prospect. In the process of harvesting, processing and utilization for Caragana, we are required to study the biomechanical properties of Caragana. These properties include physical properties, common mechanical properties, dynamics properties and rheological properties. So, we made experimental studies on these properties of Caragana stalks, fibers, formed material and reinforced composites. Obtained results will serve as a reference for harvesting, equipment designing, technology optimization and transformational utilization of Caragana materials. The main contents are as follows:(1) Caragana stalks and formed materials'tensile and compressive mechanical properties were researched by INSTRON, a kind of biological materials testing machine. The biomechanical indexes, for example tensile strength, compressive strength and elasticity modulus were tested. And the relationship between tensile stress and strain was analyzed. Besides, The correlation between indicators and some factors such as morphological specificities, age and location of Caragana stalks for 5 years and 10 years were researched. The correlation analysis results based on multivariate statistics are got. Not only the location but also the interaction between location and age are strongly correlated to the biomechanical properties of Caragana.(2) Caragana fibers of stalks for 5 years were extracted using segregation process and its tensile mechanical properties and the relationship between tensile stress and strain were researched. According to these excellent properties, the comparative advantages and good effects on the application of green environmental materials for Caragana were explored.(3) In the process of conversion and utilization for Caragana solid forming materials, we are required to study the dynamic viscoelastic properties of Caragana. It's important to forming process optimization and evaluating quality of Caragana forming materials. In the compression experiments of Caragana solid forming materials, the temperature spectra and frequency spectra of storage modulus, loss modulus and loss factor were studied by DMA (thermal dynamic mechanical analyzer). Furthermore, the movement of inner structure molecular and the dynamic viscoelastic properties such as glass transition property from the view of thermodynamics were analyzed. Obtained results will serve as a reference for transformational utilization and process optimization of Caragana environmental materials.(4) The fabrication process of agricultural facilities building materials was studied,which is consisted of cement and lime powder and strengthened by Caragana fiber,with the result of testing this composite's mechanical properties in tensile, compression and bending, acquiring its index such as tensile strength, compressive strength, elastic modulus and the limited stress of bending etc., analyzing the stress-strain relationship, exploring a new kind of approach for the application of Caragana in agricultural green environmental material.