Modal Analysis Of Three-dimension Orthogonal Woven Carbon/glass Fiber Hybrid Composites

Advanced textile composites were used as structural parts of large mechanical systems due to their strong design ability and excellent mechanical properties.Vibration of mechanical system will produce noise and shorten the service life of equipment.Therefore,the vibration and noise reduction of structures were stemmed is one of the important topics.In this paper,design and preparation of the four general fiber volume content is the same but different structures and the fiber composition of composite(three-dimension orthogonal carbon/glass fiber hybrid composite,laminated carbon/glass fiber hybrid composites,three-dimension orthogonal carbon fiber composites,three-dimension orthogonal glass fiber composite).Using experiments,finite element analysis,and numerical simulations are to study modal characteristics.First,the four reinforced structures,that is three-dimension orthogonal carbon/glass fiber woven fabric(3D orthogonal CF/GF fabric),laminated orthogonal carbon/glass fiber woven fabric(laminated orthogonal CF/GF fabric),three-dimension orthogonal carbon fiber woven fabric(3D orthogonal CF fabric),three-dimension orthogonal glass fiber woven fabric(3D orthogonal GF fabric)were designed.Then four kinds of composite materials were prepared by vacuum assisted resin transfer process,the vibration characteristics and damping performance were studied by modal test.Experimental results show that,the 3D orthogonal CF composite > 3D orthogonal CF/GF composite > the laminated orthogonal CF/GF composite > the 3D orthogonal GF composite.the 3D orthogonal CF/GF composite was all higher than those of the laminated CF/GF composite.This was because Z-binder yarns in the 3D orthogonal CF/GF composite locked all yarn sets to provide structural integrity,which can enhance its stiffness.The damping coefficient of the composites follows the following sequence: the 3D orthogonal GF composite > 3D orthogonal CF/GF composite > the laminated orthogonal CF/GF composite > the 3D orthogonal CF composite.The 3D orthogonal CF composite had the same reinforced structure and the same fiber volume fraction with the 3D orthogonal GF composite,but the damping values of the 3D orthogonal GF composite were significantly greater than those of the 3D orthogonal CF composite.This was because the damping property of GF is much larger than that of CF.3D orthogonal CF/GF composite > the laminated orthogonal CF/GF composite of damping,this is because the Z-binder yarns leading to the energy consuming from the 3D orthogonal CF/GF composite.Second,finite element method(FEM)was established to analyze the modal properties of four kinds of composite materials.The micro fiber bundle from medium unit cell to the macro homogenate composite material is obtained.Using theoretical analysis and numerical calculation method are to acquire four kinds composite elastic modulus.With the help of ABAQUS,the four composite natural frequency and modal vibration mode were carried out under the action of Lanczos solver.The finite element modal parameters good consistency with the results of experimental modal parameters is to verify the effectiveness of the prediction model.The comparison results show that the relative error between the experimental results and the calculated value of finite element based on natural frequency is low 17.8%.It is due to the FEM modeling which ignores racks and holes in the resin,the interaction between fiber and resin interfaces influenced.Meanwhile,the experiment manufacturing process was not identical,the orientation of the braided yarns specimen of the composite preform was multi-directional in the space and the braided yarns were interwoven with each other during the molding process,the braided yarn was extruded and the degree of tightness was slightly different in the spatial structure.The preforms were completed to reach a pre-stressed balance under natural conditions.Therefore,the natural frequencies of FEM were bigger experiment results.Finally,the cantilever beam model about the relationship between the natural frequency and modulus was adopted to predict the bending modulus.In order to verify the correctness of predicted values,three-point bending test was carried out to acquire the experimental values of bending modulus.The comparison results show that the relative error between experimental results and predicted values based on the first natural frequency for the four kinds of composites were all lower than 8%.Therefore,the experimental modal analysis technique as a nondestructive manner is reasonable and safe to understand the bending modulus of complex textile composites or hybrid composites,three-braided composites,three-dimensional needling composites,three-dimensional braided composites,and so on.