Vibration characteristics of filament wound composite tubes applied to the intermediate shaft in ship propulsion system

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940029
Author(s):  
Tae-Yeob Kim ◽  
Sung-Won Yoon ◽  
Je-Hyoung Cho ◽  
Yun-Hae Kim ◽  
Myung-Hyun Kim

In this study, the CFRP shafts made up of T700-SC multilayered composites have been designed to replace the steel shaft of a ship. An important design variable to be considered when designing composite material intermediate shafts is the natural frequency for resonance avoidance at critical rotational speed and torsional strength for axial load. In order to satisfy these, strength and modal analysis were performed. In order to minimize the deformation of the shape due to the residual stress after mandrel removal, it was laminated by axial symmetry. The fibers orientation angle has a great influence on the natural frequency of the drive shaft. The carbon fiber should be closely oriented at [Formula: see text] to improve the modulus of elasticity in the direction of length of the intermediate shaft and to increase the natural frequency. Also, the optimum fiber orientation for maximum torsional strength should be close to [Formula: see text]. The stacking pattern and the stacking order were finally decided considering the results of the finite element analysis (FEA).

Author(s):  
P C Tse ◽  
S R Reid ◽  
S P Ng

Closed-form solutions from complementary strain energy are derived for the spring stiffnesses of mid-surface symmetric, filament-wound, composite circular rings under unidirectional loading. A three-dimensional finite element analysis (FEA) including the effects of transverse shear has also been applied to study the problem. Four > 45° and four > 75° E-glass/epoxy composite rings of odd numbers of covers were tested. Comparisons of the results obtained from the two methods with experimental data are made and the results are found to be in good agreement. The FEA prediction of stiffness is always higher than the theoretical result. The relationships between the spring stiffnesses and the winding angles and geometry of the filament-wound composite ring are considered and discussed.


2014 ◽  
Vol 656 ◽  
pp. 288-297
Author(s):  
Krishna Murari Pandey ◽  
Abhijit Dey ◽  
P.L. Choudhury

The aim of present study was investigate the buckling pressure of moderately thick-walled filament-wound carbon–epoxy stiffened composite pressure vessel subjected to external hydrostatic pressure through finite element analysis and compare the result with un-stiffened filament wound carbon/epoxy composite pressure vessel used in under water vehicle applications. The winding angles were [±30/90] FW, [±45/90] FW and [±60/90] FW. ANSYS 14.0 APDL, a commercial finite element software package successfully predicted the buckling pressure of filament-wound composite pressure vessel with a deviation much higher than the results of un-stiffened filament wound composite cylinder .All the finite element analysis shows that the composite pressure vessel with winding pattern [±60/90] FW has the higher value of critical buckling pressure. Major failure modes in both the analysis were dominated by the helical winding angles.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 653
Author(s):  
Jinguang Zhang ◽  
Jun Rao ◽  
Lei Ma ◽  
Xianglong Wen

In this paper, based on the composite laminated plate theory and a strain energy model, the damping capacity of a Carbon Fiber Reinforced Plastics (CFRP) raft frame was studied. According to the finite element analysis (FEA) and damping ratio prediction model, the influences of different layups on the damping capacity of the raft frame and its components (top/bottom plate and I-support) were discussed. Comparing the FEA results with the test results, it can be figured out that the CFRP laminate layup has a great influence on the damping ratio of the raft frame, and the maximum error of the first-order natural frequency and damping ratio of the top/bottom plate were 5.6% and 15.1%, respectively. The maximum error of the first-order natural frequency of the I-support between the FEA result and the test result was 7.5%, suggesting that because of the stress concentration, the error of the damping ratio was relatively large. As for the raft frame, the damping performance was affected by the I-support arrangement and the simulation analysis was in good agreement with the experimental results. This study can provide a useful reference for improving the damping performance of CFRP raft frames.


Author(s):  
Emre Özaslan ◽  
Bülent Acar ◽  
Ali Yetgin

Filament wound composite structures are widely used in aerospace applications such as motor case of rockets owing to their high stiffness/weight ratio and high strength. However, design and analysis of a filament wound structure is so complex due to the anisotropic nature of the composite material. Variation of the winding angle through the rocket motor case axis and through the thickness, which is also a function of winding angle are the main challenges to the realistic modeling of a filament wound composite rocket motor case. In this study, finite element analysis of a filament wound rocket motor case with unequal dome openings was performed. The finite element model was compared with manufactured motor case in terms of winding angle and thickness to ensure the exact modeling. The finite element analysis was compared with burst tests in terms of fiber direction strain distribution through the outer surface of the motor case to verify analysis. The weak regions of the motor case were determined with finite element analysis to be transition region from cylinder to dome which is subjected to significant bending because of the stiffness difference between these regions. Then, some design improvements were proposed to increase the mechanic performance of motor case. Significant improvement was succeeded in terms of mechanic performance. Important aspects of designing and analyzing a filament wound composite rocket motor case were addressed for designers.


Author(s):  
Sarmila Sahoo

The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.


2020 ◽  
Vol 27 (1) ◽  
pp. 216-225
Author(s):  
Buntheng Chhorn ◽  
WooYoung Jung

AbstractRecently, basalt fiber reinforced polymer (BFRP) is acknowledged as an outstanding material for the strengthening of existing concrete structure, especially it was being used in marine vehicles, aerospace, automotive and nuclear engineering. Most of the structures were subjected to severe dynamic loading during their service life that may induce vibration of the structures. However, free vibration studied on the basalt laminates composite plates with elliptical cut-out and correlation of natural frequency with buckling load has been very limited. Therefore, effects of the elliptical hole on the natural frequency of basalt/epoxy composite plates was performed in this study. Effects of stacking sequence (θ), elliptical hole inclination (ϕ), hole geometric ratio (a/b) and position of the elliptical hole were considered. The numerical modeling of free vibration analysis was based on the mechanical properties of BFRP obtained from the experiment. The natural frequencies as well as mode shapes of basalt laminates composite plates were numerically determined using the commercial program software (ABAQUS). Then, the determination of correlation of natural frequencies with buckling load was carried out. Results showed that elliptical hole inclination and fiber orientation angle induced the inverse proportion between natural frequency and buckling load.


2013 ◽  
Vol 281 ◽  
pp. 165-169 ◽  
Author(s):  
Xiang Lei Zhang ◽  
Bin Yao ◽  
Wen Chang Zhao ◽  
Ou Yang Kun ◽  
Bo Shi Yao

Establish the finite element model for high precision grinding machine which takes joint surface into consideration and then carrys out the static and dynamic analysis of the grinder. After the static analysis, modal analysis and harmonic response analysis, the displacement deformation, stress, natural frequency and vibration mode could be found, which also helps find the weak links out. The improvement scheme which aims to increase the stiffness and precision of the whole machine has proposed to efficiently optimize the grinder. And the first natural frequency of the optimized grinder has increased by 68.19%.


Sign in / Sign up

Export Citation Format

Share Document