Three-dimensional Braided Composite Materials Research Articles

Nonlinear resonant responses and chaotic dynamics of three-dimensional braided composite cylindrical shell

The advanced three-dimensional braided composite structure has excellent integrity, which can effectively avoid the problems of interlayer stress jump and interface debonding that may occur in traditional composite laminated structures. However, most of the existing references on the three-dimensional braided composite structure are fragmented, and there is little research on their vibrations. Taking the cylindrical shell of a rocket as the object and considering the complex flight environment, a general framework for the vibration problems of the three-dimensional braided composite shell is proposed for the first time. The equivalent mechanical parameters of the three-dimensional braided composite material are calculated based on the volume averaging method. Then, the nonlinear dynamic model of the three-dimensional braided composite cylindrical shell is established, and the natural vibration characteristics are analyzed. Under the case of 1:1 internal resonance, the pseudo-arc length continuation method is used to solve the nonlinear resonant responses of this nonlinear system. Finally, we apply the fourth-order Runge-Kutta algorithm to study the chaotic dynamics of the three-dimensional braided composite cylindrical shell model. This framework presented in this paper can be extended to the study of nonlinear vibrations and chaotic dynamics of other three-dimensional braided composite structures.

Effect of Braid Angle on Crushing Performance of Double-Layer Carbon Fiber Composite Pipe

Three-dimensional braided composite materials have the advantages of high specific strength and good specific rigidity, they are widely used in various fields. With the help of the full-scale macrostructure model finite element analysis method to pre-test the mechanical properties of the axial compression, the simulation can observe the failure process, stress distribution and propagation form of the pipe, and study its failure mechanism. Then verify the correctness of the simulation through experiments. The conclusion is that the compressive performance of the material changes with the change in the braid angle. A smaller braiding angle can bear a larger load, but its material failure process is relatively rapid, and the load drop increases as the braiding angle decreases.

Finite-element analysis on the compression-recovery process of cotton fiber assembly

In order to analyze the compression and recovery behavior of cotton fiber assembly, and to improve the quality of cotton bales. a cotton fiber assembly model is established based on the modeling idea of three-dimensional braided composite material. At the same time, the compression modulus and recovery modulus of the cotton fiber assembly are measured by experiments. The finite-element analysis of the cotton fiber assembly is carried out with the obtained compression and recovery modulus, the recovery rate and the compression power recovery rate of the cotton fiber assembly are predicted. By further study of the effect of moisture regains on the recovery rate and compression power recovery rate of cotton fiber assembly, a referenced moisture regain value of 8.8% in cotton baling process is given. The results show that the analyzed results are consistent with the actual situation; the model has certain application value.

Complex Structure of Braid in Fiber Art Creation with Multisensor IoT Technology

Fiber-fabric composites have the characteristics of lighter texture, higher strength, higher damage resistance, better toughness, and flexibility than laminated composites, but their complex structures have not been well studied. This paper is aimed at study the complex structure of woven fabrics in fiber art creation based on multisensor Internet of Things technology and at studying the impact of its composite material mechanical properties. In this paper, it is proposed to use glass fibers and carbon fibers to weave the required structural preforms in a two-dimensional braiding machine and then use the obtained preforms and epoxy resin to prepare three-dimensional two-dimensional braided composite materials with different structures through a molding process. The composites were tested in tension, bending, and compression to obtain data and their failure modes, and the data were compared to obtain correlations. The experimental results in this paper showed that through the tensile, bending, and compression tests of the three kinds of hybrid structure braided composites, the tensile properties of the glass fiber braided composites decreased by about 77%; the influence of angle on the bending properties of carbon fiber braided composites has the largest downward trend of 63%. Two-dimensional biaxial and two-dimensional triaxial preforms are made by weaving glass fiber and carbon fiber, and the angle deviation is basically kept within 2.2%.

Investigation of Thermal and Mechanical Properties of Three-Dimensional Braided Composite Materials

Investigation of Thermal and Mechanical Properties of Three-Dimensional Braided Composite Materials

Temperature and structure effects on the impact damage distribution of 3D braided composites

Three-dimensional braided composite materials are prepared by fiber bundle braiding and composite material forming. These materials can realize the integration of material structure to manufacture complex structural parts in a near net-shape way and reduce the number of assembly connections. This material has been widely used in the aerospace industry, high-speed vehicles, and important civil facilities. Computed tomography (CT) and finite element method (FEM) were used to characterize the relationship between the internal damage distribution of 3D braided carbon fiber/epoxy resin composites under multiple transverse impact loading, ambient temperature, and microstructure. It is determined that with an increase in the temperature, the failure mode of resin changes from brittle failure to ductile failure, the interface bond strength decreases, and the failure mode changes to fiber/resin interface cracking and resin debonding. With an increase in the braiding angle, the failure mode changes from interface cracking to resin debonding cracking; interface cracking simultaneously occurs, impact tolerance increases, and local temperature increases with an increase in the absorbed energy. With an increase in the number of impacts, the accumulation of impact damage leads to the clear cumulative effect of reinforcement deformation, interface cracking, and resin debonding.

Multiple transverse impact damage behaviors of 3-D-braided composite beams under room and high temperatures

Three-dimensional braided composite materials have been widely applied to engineering structure manufacturing. It is of a great importance to characterize the impact damage of the three-dimensional braided composite under various temperatures for optimizing the engineering structure. Here we conducted transverse impact deformation and damage of three-dimensional braided composite beams with different braiding angles at room and elevated temperatures. A split Hopkinson pressure bar with a heating device combined with high-speed camera was employed to test multiple transverse impact behaviors and to record the impact deformation developments. The results indicated that failure load, initial modulus, and energy absorption decreased with the increase of temperature, whereas the deformation increased slightly with elevated temperatures. We found that the impact brittle damages occurred earlier and the local adiabatic temperature raised higher when the temperature is lower than the glass transition temperature (Tg) of epoxy resin. While above the Tg, the impact ductile damages occurred later and the local temperature raised lower. The thermal stress distribution along the braiding yarn leads to cracks propagation in yarn direction. Part of the impact energy absorptions converted into thermal energy. In addition, the beam with larger braiding angle has high damage tolerance and crack propagation resistance.

Damage detection of three-dimensional braided composite materials using carbon nanotube thread

AbstractStructural health monitoring (SHM) takes advantage of the recent advances in structural behavior monitoring to assess the performance of a structure, identifying the damage in the early stage. In this study, a carbon nanotube thread strain sensor was fabricated into a three-dimensional (3D) braided composite preform for the strain sensing of SHM. We present the results of an investigation on a carbon nanotube thread network in 3D composites for damage detection, in which the variation of the electrical resistance of the carbon nanotube thread embedded into 3D composites was recorded. Based on the variation of the electrical resistance, the location and size of damages were estimated by the response surface method, providing an effective solution for the estimation of the location and size of damages in 3D composites.

基于免疫算法的碳纳米管线传感器网络优化配置

针对三维编织复合材料结构健康监测中碳纳米管线传感器网络的优化配置问题，根据检测覆盖范围最大且传感器数量最小的原则，提出了一种基于免疫算法的求解方案。该方案将要求解的传感器位置作为抗体，设计了抗体编码方式以及免疫算法的过程。仿真实验结果表明，免疫算法能够有效地求得最佳解决方案。 According to the optimization allocation of three-dimensional braided composite material of carbon nano pipeline sensor in the sensors network to monitor material structure and keep structure health, in consideration of the principle of coverage maximum and sensor number minimum, an immune optimization algorithm was proposed. It designed individual antibody coding and the process of the immune algorithm. Finally, simulation results show that the immune algorithm can effectively obtain the best solution.

Fatigue behaviors of four-step three-dimensional braided composite material: a meso-scale approach computation

This paper reports the computational results of the bending fatigue behaviors of four-step three-dimensional rectangular braided composite materials from a meso-scale approach. A full-size meso-scale model of a four-step three-dimensional braided composite was established to numerically analyze the deformation and damage under cyclic bending loading. The stress distribution, energy absorption, hysteresis loop features and damage morphologies were obtained to explain the structural effects on the deformation and damage of the three-dimensional braided composite material subjected to three-point bending cyclic loading. The influences of the microstructure on the fatigue behaviors have been discussed for designing the three-dimensional braided composite material with high fatigue damage tolerance.

Wavelet Transform Applied on Noise-decreasing of AE in Three-dimensional Braided Composite Material

Wavelet Transform Applied on Noise-decreasing of AE in Three-dimensional Braided Composite Material

Three-Dimensional Braided Composites Detection Method Based on Improved Chaotic Neural Network

Three-dimensional braided composite materials for the use occurred during the fracture, deformation and other injury problems, a distributed Bragg grating sensor applied to detection of parts in health status. With three-dimensional braided composite weaving, research on the mechanical properties of small parts, sensors embedded in the sensor signal processing easy way. Embedded in three-dimensional composite parts of the sensor network signal processing method, the rapid implementation of distributed signal processing and the structure of large parts of the distributed monitoring.

Research on Acoustic Emission Signal of Three Dimensional Braided Composite Material

This paper discusses the application and experimental method of acoustic emission for the three-dimensional (3D) braided composite material under flexural testing. It describes the feature of acoustic emission when applied to three-dimensional braided composite material under flexural testing. In order to know the materials damage position precisely, it is very important to collect the signal of acoustic emission source. The results of flexural experiment show that it is precise on the research of acoustic emission source location by the method of wave form analysis .During the collecting signal of acoustic emission , it is compared between parameter analysis and wave form analysis. According to the attenution degree of signal, it is selected signal of acoustic emission source exactly. It is the method to extract the precise acoustic emission signal by the different algorithm of wavelet analysis. We know that humans have been using materials by testing activities support, these tests have developed several centuries. From the traditional rough test to support materials and materials used in all aspects of science and technology, modern, scientific program, at present, there are mutual dependencies between the progress of scientific knowledge and the development of test methods. The 3D braided composite material is a kind of complex structure. Because of the many components and weaving material preparation process characteristic, material mechanics behavior is very complicated. It is characteristics of the 3D braided composite material, that the application on composites is widely more and more. The 3d braided composites have been used widely in aerospace, aviation, transportation, chemical, sports, medical care and other fields, so it is extremely vital significance for research on mechanics performance analysis of 3D braided composite material. Current studies of damage fracture behavior of composite materials are used in homogeneous materials research methods, namely the mechanical test and microscopic observation, but the research cannot distinguish and identify different damage fracture source, due to the combination of mechanical test parameters of the complex fracture micro-mechanism not sensitive. Microscopic observation is in fact observation later, local fracture surface morphology research, so can not observe the interaction of numerous fracture source and micro behavior, and can not study in the character of fracture source of composite materials, therefore the source faults already can not adapt to the traditional methods of composite material damage fracture process. From external or internal force effect material and structure produced deformation or fracture with elastic wave form, the strain energy release phenomenon called acoustic emission or stress wave [1]. Acoustic emission testing method is a kind of material internal defects or potential defects in the dynamic changes in movement, the damage detection method is real-time monitoring and can reflect the characteristics of acoustic emission sources in the load of the dynamic response. The AE information can directly reflect defects and changes [2, 3].

Research on Health Monitor for Three-Dimensional Braided Composite Material

This paper describes two methods of Fiber Bragg Grating (FBG) embedded in the three-dimensional (3D) braded composite materials and acoustic emission health monitor for 3D braided composite materials condition. The paper mainly analyses the relations of FBG change and the inner straining under the stretching on materials. It is provided that the way of signal collection and processing. The experimental results proved that FBG sensors have exceptional sense characteristic. The braided angle of composites has a little influence on FBG signal. FBG embedded in the 3D braided composite materials has not more effect mechanical property of materials. According to two health monitoring methods and the particularity of 3D braided composites, the health monitoring method based on FBG much more applies to dynamic monitoring on 3D composites special field. This research provides basis for the study and application of advanced intelligent composites.

Research on Health Monitor for Three-Dimensional Braided Composite Material Products Condition Based on FBG

This paper describes the method of Fiber Bragg Grating(FBG)embedded in the three-dimensional(3D) braded composite materials and provides the method of health monitor for 3D braided composite materials condition. The paper analyses the relations of FBG change and the inner straining under the stretching on materials. It is provided that the way of signal collection and processing. In the process of load-supporting, the internal local strain of 3D braided composites is much more, and local strain has certain interference on embedded near FBG output. The experimental results proved that FBG sensors have exceptional sense characteristic. The braided angle of composites has a little influence on FBG signal. FBG embedded in the 3D braided composite materials has not more effect mechanical property of materials. This research provides basis for the study and application of advanced intelligent composites.

Analysis of nonlinear vibration of a motor–linkage mechanism system with composite links

This paper studies the nonlinear vibration of a three-phase AC motor–linkage mechanism system with links fabricated from three-dimensional braided composite materials. Taking the drive motor and the linkage mechanism as an integrated system, the dynamic equations of the system are established by the finite element method. The relation between the nonlinear vibration of the system and the parameters of the system is obtained by the method of multiple scales. Results show that not only the structural parameters, but also the electromagnetic parameters and the material parameters have significant effects on the nonlinear vibration of the system. Finally, a numerical example is presented.

The Dynamic Equation and Simulation of a Linkage Mechanism Fabricated from Three-Dimensional Braided Composite Materials

The work in this paper is concerned with a four-bar linkage mechanism with links fabricated from three-dimensional braided composite materials. The dynamic equation of the mechanism is established by finite element method (FEM), it includes composite materials parameters and structural parameters of the mechanism. The mass matrix of the beam element is obtained in light of the mass distribution characteristics of the composite materials. According to the 3-dimensional microstructure characters of the three-dimensional braided composite materials, the anisotropic beam element is considered to be made up of four parts, and then the stiffness matrix of the beam element is derived from the constitutive equations of each part and the relation between the strain distribution of each part and the node displacement of the beam element. Based on the damping element model and the expression of dissipation energy of the 3-dimentional braided composite materials, each modal damping value of the mechanism is calculated and the damping matrix of the mechanism is established. The dynamic responses and natural frequency of the mechanism are obtained by simulation, respectively. The work presented in the paper provides theoretical basis to a certain extent for the further research on nonlinear vibration characteristics and optimum design of this kind of mechanism.