**Abstract**

The materials involved in the fabrication of biocomposites have dissimilar physical and chemical properties. More important, the newly created materials exhibit anisotropy and their performance is strongly influenced by the hydrophobic nature of the natural fibers used as reinforcement materials. Beyond a compressive discussion regarding the potential of composite materials with natural fibers in engineering applications, the chapter focuses on simulation of their behavior under applied loads. Modern experimental approaches for defining and validating computer simulations are also introduced. Finally, health hazards and biodegradability issues are evaluated. The new trends in biocomposites materials for engineering applications are briefly discussed.

**Keywords:** biocomposites classification, anisotropy, hydrophoby, simulation and experimental trends, health hazards

## **1. Introduction**

Environmental and economic considerations recommend the employment of natural fibers as reinforcements in polymeric matrices. The matrix protects the fibers from environmental degradation and by doing so it preserves its mechanical strength. Natural fibers have lower density than artificial fibers, are a renewable material and in most cases are recyclable. The absolute tensile strength of natural fibers is lower than the tensile strength of artificial fibers, as shown in the schematic representation from **Figure 1**. However, due to their lower density, natural fibers have a higher specific tensile strength – defined as the ratio between the absolute tensile strength and the mass density – which makes them ideal candidates for composites employed in aerospace applications.

There are important variations in the physical and chemical properties of natural fibers, variations depending on age, geographical location and age. Such variations must be considered in any design and evaluation of composites with natural fibers and statistical evaluations of strength are important.

Natural fibers are hydrophobic and anisotropic. Such properties pose challenges to the designer and manufacturer of biocomposites. The need to control the content of water in natural fibers requires specific chemical treatment in order to maximize the bond fiber-matrix. The mechanical properties of biocomposites need to be rigorously evaluated by precision experiments and statistical evaluations designed

to assure reliable input parameters for the computer modeling and simulation of components made from such materials.

This chapter introducer the reader to key aspects encountered in the classification of natural fibers. The performance evaluation, benefits and disadvantages of designing, manufacturing and employment of biocomposites in a wide range of industrial applications are also discussed in some detail.
