EFFECT OF ELASTIC MODULI (E1 AND E2) OF A HYBRID COMPOSITE ROD AND ITS CONSTITUENTS ON FREE TORSIONAL NATURAL FREQUENCY | ||
| Al-Qadisiyah Journal for Engineering Sciences | ||
| Article 1, Volume 9, Issue 3, September 2016, Pages 368-387 PDF (0 K) | ||
| Authors | ||
| Ali Abdulhussien Abdulameer Al-Dhalmi; Luay Muhammed Ali Ismaeel | ||
| Abstract | ||
| 1. Abstract: In this work, a hybrid fiber reinforced composite rod fixed from one end, while the other end is left free and subjected to a static torsional load, and left to vibrate freely after load releasing. Fiber volume fraction of 40% is considered to rod of interest, the matrix is composed of 20% short fibers and 40% pure matrix (this type of matrix is called composite matrix, which is well known and widely used in fiber reinforced hybrid composites). Such a ratio is adopted since it gives enough strength and reinforcement and meet the economic requirements as well, as mentioned in Mechanics of Composite Materials by Jones 1999. Four various long and short fibers of the same type and four matrices are taken to construct the rod in order to introduce the different properties to investigate their effects on natural frequency under torsional excitation. The problem is manipulated using software of AnsysV.14. The elastic properties of materials are determined using software of Matlab v.7. The results show that natural frequency is mainly highly affected by matrix longitudinal elastic modulus than that of fibers, and displays a regular pattern of behavior. The fibers show an irregular behavior towards the natural frequency variation. This can be attributed to the interaction effects between three types of constituents, matrix, long and short fibers composing the whole structure of the rod. In addition, there is the effect of anisotropy of material effective elastic properties, which plays an important role in results irregularities. | ||
| Keywords | ||
| Key Words; Natural frequency; Torsional vibration; elastic moduli; Constituents; Hybrid composite Rod | ||
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