Composite Tubes Research Articles

Effectiveness of composite energy dissipation restrainer on mitigating pounding and unseating failure of highway bridges

In earthquake-prone regions, large relative displacement between piers and girders may lead to pounding damage and unseating failure in highway bridges. To mitigate these effects, this study presents a composite energy dissipation restrainer (CEDR) that incorporates a composite energy tube (CET) as a fundamental component (comprising an aluminum honeycomb buffer and an expansion tube). The energy absorption characteristics of the CET are analyzed, and the influence of the aluminum honeycomb is thoroughly discussed. Furthermore, a design procedure and mechanical model for the CEDR, considering rare earthquakes, are developed. Finally, the effectiveness of the proposed design method and the behavior of limiting displacement of the CEDR are demonstrated through nonlinear time history analysis of an implemented project. The results reveal that the aluminum honeycomb buffer exhibits superior energy absorption capability, enhancing buffering efficiency and reducing damage. Compared to common cable-type restrainers (CCR), the CEDR reduces the relative peak displacement of the bridge by 40%, decreases the frequency of reciprocating displacement by 30% on average, and mitigates impacts on the abutment by 80%.

Effect of geometric structure and fiber orientation on crashworthiness of honeycomb‐inspired composite thin‐walled tubes

AbstractThis study investigates the crashworthiness of biomimetic composite thin‐walled tubes under quasi‐static axial crushing, focusing on the effects of geometric structure and fiber orientation. The thin‐walled tubes, inspired by honeycomb structures, were manufactured using carbon fiber composites through multi‐cavity preform mold method. Quasi‐static crushing tests and CT scanning observation were conducted to characterize the mechanical response, crashworthiness mechanisms and energy absorption capacity of the thin‐walled tubes. Results demonstrated excellent energy absorption capacities across all configurations, with the C‐0/45 configuration achieving the highest specific energy absorption at 115.03 kJ/kg. The optimal crushing energy absorption process for thin‐walled tubes involves achieving high peak loads and maintaining high load levels. Sustaining high loads requires progressive and stable damage without the formation of extensive intermediate cracks between different plies (indicative of strong interlaminar shear strength). The structural integrity of the uncrushed sections must remain intact without significant damage during the crushing process. Fiber orientation parallel to the loading direction enhances peak load levels and interlaminar shear strength between plies, but may compromise circumferential stiffness and structural stability. The influence of geometric configuration is primarily manifested in the progressive and stable crushing phase, where the tube requires sufficient space to accumulate its own debris without causing damage to the uncrushed thin‐walled structure.Highlights Structures and fiber orientation boost crashworthiness in biomimetic composite tubes. Biomimetic structures were produced using a multi‐cavity preform mold method. CT scans were conducted to characterize the energy absorption mechanisms. Composite tubes demonstrated excellent energy absorption capacity of 115 kJ/kg.

Acoustic emission source location for composite tubes using finite element simulation and machine learning

ABSTRACT Acoustic emission is widely used in engineering structural health monitoring, where damage location based on acoustic emission have great advantages. Currently, most of the acoustic emission location work requires extensive experimental studies. In this study, acoustic emission source location model was proposed based on BP neural network and acoustic emission wave propagation simulation, thus reduced the experiments required for acoustic emission localisation and improved the location accuracy. Initially, finite element simulation was conducted to study the propagation of acoustic emission waves in composite tubes. The calculated findings showed a high level of agreement with the experimental data. Additionally, the first arrival time of the signal was extracted according to the Akaike information criterion, and the neural network was trained and tested using the simulated data, while the trained network model was validated using the experimental data. The results show that the finite element method is a reliable alternative test method. More than 94% of the sound source location results have absolute location error within ± 3 mm, and the all points is less than ± 5 mm. The deviation of the location results showed significant improvement compared to the traditional time difference of arrival method, verifying the feasibility of the method.

Analysis of multi-scale failure behavior of SiCf/SiC composite clad tube under flexible clamping damage

The intricate spatial fiber winding structure of SiCf/SiC ceramic matrix composite (CMC) cladding tubes makes it difficult to investigate in depth the inherent evolutionary mechanism of damage failure under specific operating conditions. Therefore, in this study, based on X-ray computed tomography (X-CT) reconstruction and cross scale numerical simulation methods, combined with clamping failure experiments under specific conditions for the cladding tubes, we conduct an in-depth analysis of the material's damage, failure, and mechanical behavior in different clamped regions. The research indicates that variations in the clamped regions have a minimal impact on the overall mechanical feedback of the material, and the maximum clamping load remains essentially around 500 N. The tube damage exhibits a unique " regional progressive damage evolution mechanism," where stress differentials of 108.49–115.33% appear between the inner and outer surfaces in different regions, leading to variations in the initiation and propagation of cracks within these areas. Furthermore, based on the minimum potential energy principle and semi-geodesic line theory, the intricate macroscopic tube structure formed by the spatial stacking and winding of SiCf/SiC cladding tube fibers is accurately reconstructed, which is combined with macroscale and microscale local feature models to capture the fibre/matrix morphology of the material with dynamic mechanical feedbacks, and experimentally validated in this work. The results indicate that the numerical model can effectively characterize the complex mechanical damage morphology and progressive failure lows of SiCf/SiC CMC at multiscale. Simultaneously, it is observed that stress concentrations in the fiber crossover region result in a load-bearing capacity 112–283% higher than in other areas. This phenomenon often leads to the first occurrence of failure in this region after clamping overload, exhibiting more pronounced damage characteristics.

Quasi-static crush response of lightweight sandwich composite tubes fabricated via newly designed internal thermal expansion technique

Different from conventional unidirectional outward-inward forming methods, this study employs a multidirectional internal expansion shaping approach to fabricate lightweight sandwich composite tubes. Integrating carbon fiber reinforced polymer (CFRP), thermal expansion foam and polymethacrylimide (PMI) foam, the sandwich composite tubes demonstrate adaptability in terms of material properties as validated through several experimental trials. The one-step molding process eliminates the requirements for subsequent structural assembly and bonding, while ensuring adhesion between diverse material components. The sandwich composite tubes exhibit superior impact resistance, showcasing a stable progressive crushing failure. The energy absorption mechanism shifts from single CFRP damage to a multi-material composite energy absorption mode. The specific energy absorption (SEA) value of designed sandwich composite tube is up to 102 J/g. The sandwich composite tubes fabricated in this study hold promising applications in advanced vehicle/aerospace lightweighting and crashworthiness safety.

Effects of Darcy and Viscous Dissipation on Natural Convection Flow in a Vertical Tube Partially Filled with Porous Material under Convective Boundary Condition

In this paper, a study is presented considering the effects of Darcy and Viscous dissipation in a steady natural convection incompressible fluid through a vertical composite tube partially filled with a porous material. The fluid motion in the vertical composite tube is caused by a temperature gradient due to heat applied to the wall of the tube. The Brinkman Darcy extended model was used to stimulate the fluid flow under the working fluids of water and air. The Homotopy pertubation method was used to solve the temperature and velocity equations in both the clear and porous fluids. An increase in the Brinkman number increases the temperature and velocity profiles of both working fluids. An increase in the thickness of the porous material can be used to increase the velocity of the fluid in the composite vertical tube. An increase in the internal conductive resistance leads to a decrease in the buoyancy force and, as a result, the fluid thickness, which leads to a decrease in the velocity of the fluid.

Experimental investigation of probabilistic failure of SiC/SiC composite tubes under multiaxial loading

This paper presents an experimental investigation of the failure behavior of SiC fiber-reinforced SiC matrix (SiC/SiC) composite tubes under multiaxial loading. A new testing apparatus is designed to independently apply axial stress and internal pressure to SiC/SiC tubes. Acoustic emission (AE) is used to monitor the damage growth in the specimen. Based on the measured stress–strain response, a strain-based criterion is proposed to determine the proportional limit stress (PLS). The proposed strain-based criterion is compared with the PLS determined by the AE measurement. The PLS is determined for different loading ratios to form a multiaxial failure surface. By testing multiple replicates, the statistical variations of the PLS are determined. Based on the experimental results, a mathematical model is developed to characterize the probability distribution of the PLS of SiC/SiC composites under multiaxial loading.

A study on low-frequency vibration mitigation by using the metamaterial-tailored composite concrete-filled steel tube column

The bandgap properties exhibited by local resonant metamaterials provide a potential approach for structural vibration reduction. In this work, we introduce the local resonance mechanism into the composite structure for the first time and propose a novel metamaterial column with 33.8–47.2 Hz low-frequency vibration mitigation based on practical engineering materials and utilizing material shear deformation. By vertically arranging metamaterials, the metamaterial concrete-filled steel tube column with low-frequency vibration reduction bandgap is designed. Its equivalent bandgap model is proposed by combining the Timoshenko beam and Bloch theorem. The bandgap formation mechanism and vibration mitigation effect of the metamaterial are clarified by finite element analysis. It is revealed that the bandgap generation depends on the contrary motion between the resonator and the substrate, thus the reaction force from the relative motion can cancel the external excitation. Then, the bandgap vibration mitigation effect of the metamaterial column is proved by shaking table tests at different amplitudes. This also supplies a feasible solution for vibration mitigation control and even earthquake protection for buildings, bridges, and major infrastructures. Finally, the theoretical, numerical, and experimental results are discussed to verify the validity of the theoretical approach and numerical model, and the rubber damping is found to widen the bandgap but weaken the vibration reduction capacity.

Torsional actuation and vari-stiffness characteristics of SMA/basalt hybrid braided composite tubes

Shape memory alloy hybrid composite (SMAHC) tubes have the potential to actively control the torsional stiffness of structures. In this work, shape memory alloy (SMA) wires orthogonally braided with basalt fiber were heated by electricity to generate the torsional torque of the SMAHC tube, and then the torsional stiffness of the tube was measured. The macroscopic finite element model of the SMAHC tube was established to assist in the analysis of the torsional stiffness variation before and after heating. According to the experimental results, the actuating torsional ability was affected by the phase transformation recovery force of SMA. The active control of torsional stiffness depends on the change of SMA modulus, the magnitude and direction of SMA wires’ recovery force, and the thermodynamic properties of matrix at different temperatures. Then an evaluation model for the torsional stiffness control effect was proposed. These research results can be used for the adaptive control of the stiffness and vibration characteristics of rotating composite structures, and provide a novel and effective method for the control of structural torsional characteristics with lightweight effects.

Low Velocity Impact Monitoring of Composite Tubes Based on FBG Sensors.

Carbon fiber reinforced composites (CFRP) are susceptible to hidden damage from low velocity external impacts during their service life. To ensure the proper monitoring of the state of the composites, it is crucial to predict the location of an impact event. In this paper, fiber Bragg grating (FBG) sensors are affixed to the surface of a carbon fiber composite tube, and an optical sensing interrogator is used to capture the central wavelength shift of the FBG sensors due to low-velocity impacts. A discrete wavelet transform is used for noise reduction in the response signals. Then, the differences in the captured response signals of the FBG sensors at different locations of the impact were analyzed. Moreover, two methods were implemented to predict the location of low-velocity impacts, according to the differences in the captured response signals. The BP neural network-based method utilized three data sets to train the neural network, resulting in an average localization error of 20.68 mm. In contrast, the method based on error outliers selected a specific data set as the reference dataset, achieving an average localization error of 13.98 mm. The comparison of the predicted results shows that the latter approach has a higher predictive accuracy and does not require a significant amount of data.

The influence of drilling-induced damages and hole quality on hoop tensile and fatigue behavior of CFRP tubes

Filament winding and roll wrapping methods are widely used in the production of composite tubes. While the mechanical behavior of composites produced by different methods may be different, the effects of the damages that occurred while machining composite tubes on the mechanical behavior may also be different. In this study, the effects of drilling-induced damages and hole quality on the tensile and fatigue strength of the filament-wound and roll-wrapped composite tubes were experimentally investigated. Results showed that while the behavior of the filament-wound composite tube under hoop tensile load is better than the roll-wrapped composite tube, the roll-wrapped tube performs better than filament-wound tube under hoop fatigue load. It was also observed that different drilling conditions affect the mechanical behavior of filament-wound tube while it was found that drilling conditions do not have a significant effect on the mechanical behavior of roll-wrapped tube because manufacturing defects are more dominant.

Transverse impact response of GFRP tubes filled with MWCNT-reinforced syntactic foam

Tubular composites made of glass fiber reinforced polymer (GFRP) have been widely used in the fields of infrastructure and automobile engineering. However, such composites are vulnerable to transverse loading occurrences and their effect on structural integrity. This paper focuses on investigating the response of hollow GFRP tubes and GFRP tubes filled with syntactic foam under transverse impacts. To enhance the stiffness of GFRP tube and improve the brittleness of syntactic foams, ribs were added to strengthen the tube wall, and multiwalled carbon nanotubes (MWCNTs) were used to reinforce the syntactic foam core. The impact response of the tubes was examined by considering the influence of ribs, MWCNTs, and the impact location. Experimental results revealed that the ribs contributed to enhancing the impact resistance of both hollow and filled tubes. However, the impact of ribs on energy absorption was less noticeable for the filled tubes. Incorporating 1.2 wt.% MWCNTs in the foam resulted in significant improvements of 25 % in peak impact force and 43 % in energy absorption for the filled tubes. Changing the impact location from the tube wall to the rib led to a significant increase of 33 % in peak impact force and 18 % in energy absorption for the hollow tubes. In contrast, the impact location had a minimal effect on the overall impact responses of the filled tubes. An analytical model was developed to predict the energy absorption capability of the composite tubes. This model accurately determined the energy absorption contribution of each component within the composite tube. The predicted results demonstrated good agreement with the experimental findings, validating the predictive capability of the model. Furthermore, multiscale finite-element (FE) models were developed to simulate the impact characteristics of foam-filled composite tube specimens. The validated FE model was subsequently utilized to conduct parametric study.

Experimental study and finite element analysis on axial compression performance of CFRP-PVC confined coral seawater and sea-sand concrete columns

In this paper, a composite column using carbon fibre reinforced plastics and polyvinyl chloride composite tube (CFRP-PVC) to constrain coral aggregate seawater sea-sand concrete (CSSC) was proposed, and CFRP was pasted on the inner and outer walls of the PVC tube. To investigate the effects of the number of CFRP layers and void defects on the axial compression performance of PVC tubes, six specimens were made for axial compression loading tests and finite element parameter analysis. The results indicate that due to PVC improving the integrity of CFRP, PVC tube provide a stress transfer path for CFRP, placing CSSC in a triaxial compression state. When both the inner and outer walls of the tube are pasted with CFRP, brittle failure of CFRP-PVC tube can be effectively avoided and have relatively superior mechanical properties. In the same situation, when one layer of CFRP is pasted on the inner wall of the tube, it has better ductility and bearing capacity. When two layers of CFRP are pasted on the outer wall of the tube, the coefficient of constraint stress increase is as high as 121.5%, and the void defect only has a significant impact on ductility. A finite element model of CFRP-PVC confined CSSC columns considering Hashin damage criterion was established based on ABAQUS, accurately predicting the failure process and CFRP damage morphology of test columns under axial load. Parameter analysis shows that when the confinement coefficient of CFRP-PVC confined CSSC columns is less than 0.3 and the height-diameter ratio is greater than 15, the load-displacement curve will lose the strengthening stage, and increasing the number of outer CFRP layers will slightly increase the stiffness of the strengthening stage. A bearing capacity calculation method suitable for CFRP-PVC confined CSSC was proposed based on the model of steel tube confined concrete, with an error of 1.2%.

THE EFFECT OF DIFFERENT WINDING CONFIGURATIONS ON THE CRUSHING RESPONSE OF HELICAL WOUND WOVEN GLASS/EPOXY COMPOSITE TUBES

The crushing behavior of polymer matrix composite tubes depends on several factors, such as diameter, fiber orientation, wall thickness, and winding configuration. The current work aims at understanding the effect of winding configuration with different helical overlap portions (none, quarter, and half) and the number of layers on the crushing response of woven glass/epoxy composite tubes subjected to quasi-static compression and impact loading. The length-to-diameter ratio is kept constant, for all the cases of the specimen considered. Crashworthiness parameters, such as mean crushing load, initial peak load, specific energy absorption, and crush load efficiency are compared for different cases. Damage and failure characteristics of different helical wound composite specimens are examined and compared with straight wound composite tubes made with a winding angle of 0°. The study shows that the energy absorption capacity of helical wound specimens increases in almost the same proportion as the helical overlap portion increases from no overlap to half overlap. Also, experimental results for composite tubes having different helical overlap portions suggest that the helical overlap portion can be an important parameter in achieving tailor-made energy absorption properties with inbuilt triggering features.

Numerical simulation of flow and heat transfer of n-decane in composite tube under supercritical pressure

As scramjet propulsion systems face big challenges in thermal protection performance, regenerative cooling techniques have been proposed to improve heat transfer behavior. This study introduced a novel design of composite cooling channel with bends and conducted computational fluid dynamics (CFD) simulations to analyze the flow characteristics, heat transfer behavior, and pyrolysis of hydrocarbon fuel within the tube. Results show that the presence of bends significantly enhances heat transfer, leading to an increased temperature and conversion. The composite tube with 15 bends demonstrated a 19.9% increase in conversion rate compared to the straight tube. Hence, proper structure design can improve the regenerative cooling performance which may promote the development of scramjet propulsion systems.

Experimental Study on Axial Thermal Expansion of Composite Thin-walled Tube

Carbon fiber reinforced composite thin-walled tubes have the characteristics of light weight, high strength and small deformation, and are widely used in aviation, aerospace and other fields. Under the working conditions of high and low temperature, the thermal deformation of tube will directly determine the service reliability of their constituent structures. It is necessary to accurately measure the thermal expansion performance of composite thin-walled tube and reasonably evaluate the stability of their constituent structures. When the existing thermal expansion performance measurement system measures the thermal expansion of tube, there are problems of sampling damage to the structural state and failure to effectively contact the end face of tube in real time. For the above situations, A method for measuring the axial thermal expansion performance of composite thin-walled tube is proposed, and the measurement system is built. The thermal expansion performance of thin-walled tube is successfully and effectively evaluated, and the error of the measurement system is reasonably evaluated using the standard parts with known thermal expansion coefficient.

Numerical evaluation of damage in laminated composite tubes under low-speed impacts

The use of advanced composite materials is becoming more and more frequent in structures that support great effort due to having a higher specific stiffness, which allows for reducing the weight of structures. The manufacturing methods associated with this type of material mean that the reinforcement element, the fibre, has its integrity easily reached with the occurrence of small impacts. The present study aimed to obtain a numerical evaluation of the performance of carbon fibre-reinforced polymer (CFRP) tubular profiles subjected to transverse low-speed impact, using FEM (Finite Element Method) code based. The crucial point of the study was to promote various impact tests with different energy levels and correlate with the strain results, defining for the purpose tube, the energy limit that produces residual deformation. Laminated composite tubes subjected to low-velocity impacts could suffer permanent deformation even when it is not eye-visible. Some of these invisible damages could promote a crack initiation in tube layup, reducing the fatigue life of specimens. This study allowed to obtain a classification of the structural integrity of a composite tube under gradient low-speed impact tests, which represents a piece of important information to establish a parallelism between the residual strength and fatigue life in experimental testing.

Mechanism and Influence Research on the Bending and Torsion Damping of Composite Hollow Tube

The internal damping has a significant influence on the dynamic performance of carbon fiber-reinforced plastic (CFRP) drive shaft. In this paper, the traditional damping strain energy model of composite structures was modified using the reverse off-axis transformation. The damping ratio of CFRP hollow tube pieces is then tested using the vibration method, and the accuracy and efficiency of the modified damping numerical model are verified. Meanwhile, the modified model was proposed to study the damping characteristics and contribution rate of the CFRP hollow tube. The results show the influence law of the laminate parameters on the bending and torsion damping of the CFRP hollow tube. How the strain energy dissipation affects the damping of the CFRP hollow tube is discussed, and the mechanism relationship between the laminate parameters and damping is explored. This study provides theoretical guidance for the design of the bending and torsion damping of CFRP hollow tube.

Lateral compression behavior of expanded polypropylene foam-filled carbon fiber reinforced polymer and aluminum/carbon fiber reinforced polymer composite tubes: An experimental study

This study investigates the energy-absorbing capability of the circular cross-section carbon fiber reinforced polymer (CFRP) and Aluminum/CFRP (Al/CFRP) composite tubular structures under quasi-static lateral compression. The CFRP composite tubes were manufactured with the 6, 8, and 10 layers to observe the thickness effect. A specially designed and manufactured polymer mold was used to manufacture identical CFRP composite tubes. Expanded polypropylene (EPP) foam with densities of 30 kg/m3, 60 kg/m3, and 75 kg/m3 was chosen as a filler material to enhance the energy absorption and efficiency because of its superior properties of high strength-to-weight ratio. The experiments revealed that the carbon fiber layer number directly affected CFRP and Al/CFRP composite tubes' force and the absorbed energy values. The increase in the maximum and average force values is more evident than in the Al/CFRP tubes due to using aluminum tubes constraining the effect of the carbon woven part. Additionally, EPP foam filling significantly contributes to the tubes' absorbed energy. The absorbed energy increased proportional to the foam density, and the 10-layer Al/CFRP tube filled with 75 kg/m3 sample absorbed the highest energy value as 257 J. However, considering the crashworthiness parameters (i.e., specific energy absorption, crush force efficiency, and work effectiveness), the best sample combination did not absorb the highest energy. Although the 6-layer CFRP composite tube absorbed the lowest energy, it has higher specific energy absorption and work effectiveness. According to the crashworthiness parameters, the best efficiency was obtained in the 10-layer composite tubes filled with 75 kg/m3.

Torsional Fatigue and Static Torsion Strength and Test Validations of Composite Tube Hybrid Drive Shafts

Drive shafts are the transmission components which transfer power from power source to required location. The connection may be between steering wheel and rack & pinion mechanism or gearbox to differential. As in gearbox to differential connection, operational conditions are harsh and high loads are generated, steel materials are mainly preferred to be used. Though steels have such advantages in cost, performance and durability, it is heavier compared to other engineering materials. Since international regulations dictate to decrease the carbon emissions rates due to global concerns, weight decrement of automobile components plays an important role in solving such problem. Considering the operational requirements and boundary conditions, weight reduction in steel parts might be tough. For this reason, alternative materials must be deeply investigated and implemented into the traditional technologies. In the scope of this study, fatigue and torsional strength of propeller shaft with composite tube and aluminum subcomponents were investigated.