scholarly journals Study of stability loss of cylindrical shell made of composite material

2021 ◽  
Vol 18 (3) ◽  
pp. 342-350
Author(s):  
L. A. Adegova ◽  
M. V. Bobrysheva ◽  
A. E. Scherbinina

Introduction. Composite materials are used in the construction of transport infrastructure facilities, buildings and structures for various purposes, in housing and communal services. Calculation of structures made of composite materials is used in the field of stress-strain state, buckling, analysis of material under tension, the effect of cracks on the state of these structures. The main properties of composite materials and a method of manufacturing a cylindrical shell structure from a composite material are considered. The total number of winding options is calculated using the combinatorial method.Materials and methods. A composite cylindrical shell with a radius of R = 300 mm and a height of H = 600 mm was chosen as the object of research. The creation of a model of a cylindrical shell in a finite element analysis package is described. An axial compressive load acting on the shell with a force of F = 100 kN is specified. Determination of the critical force ratio.Results. The results of the analysis of the loss of stability of the cylindrical shell are obtained and the graphs of the dependence of the critical force on the options for laying the layers are presented. Depending on the magnitude of the critical force and the form of buckling, the most and least favorable options for laying layers in a composite material package have been determined.Discussion and conclusions. A conclusion is made of the dependence of the critical force on the combination of stacking layers in the composite.

2014 ◽  
Vol 1061-1062 ◽  
pp. 649-652
Author(s):  
Jing Wang ◽  
Li Ying Yang ◽  
Shou Ren Wang ◽  
Guang Ji Xue ◽  
Chang Xiu Zhou

Spherical plain bearing is a sliding bearing have a spherical contact surface,it can bear larger load and automatically adjusted to the self-alignin. TiAl-based composite material is a material that be used to lightweight spherical plain bearing. The Simulation used the finite element software Ansys for the bearing’s static analysis.The material of outer ring using normal bearing steel, one group used the TiAl-based composite materials as the material of the inner ring, Another group the inner ring material is bearing steel 9Cr18. The law of the stress and strain produced by the two groups is consistent,the deformation of the composite materials is bigger under the same load, its elasticity modulus and density is smaller compared to the ordinary bearing steel,the composite material has the advantages of high specific strength especially in the occasions have strict requirements of the bearing weight.


Author(s):  
K. N. Salloomi ◽  
L. A. Sabri ◽  
Y. M. Hamad ◽  
S. Al-Sumaidae

The current paper investigates the effect of cut-out design parameters on load-bearing capacity and buckling behaviour of steel cylindrical shell using a nonlinear finite element analysis in modelling cylinder buckling under longitudinal compressive load. The effect of four geometry design parameters: shell diameter to thickness ratio, cut-out location, orientation, and size were investigated in this study. To enhance the prediction of buckling behaviour, both geometrical and material nonlinearities were considered. An ANSYS APDL code was written and tested by verifying its validity through comparison with former buckling study. The results showed that changing the cut-out location from mid-height of the cylindrical shell towards a fixed edge caused an increase in the buckling load value. Moreover, the study showed that increasing parameters such as shell thickness and cut-out orientation have a positive influence in which the buckling load value increased too. For fast design purposes, an empirical numerical based regression formula was presented for the calculation of the critical buckling load of a cylindrical shell having an elliptical cut-out.


Author(s):  
Neville Dodds ◽  
Ketan Pancholi ◽  
Vineet Jha ◽  
Syed Fawad Tariq ◽  
James Latto

Thermoplastic composite materials are very advantageous as component layers in subsea risers due to their inherent properties such as high strength, low density, fatigue and chemical resistance. However, response of composite materials to applied loading is complex and three-dimensional in nature. The heterogeneous structure of the composite material induces irregular distribution of stress/strain over the cross-section and thus, it is essential for design to use analytical methods capable of determining the stress-strain relationship in three-dimensional space. Currently, most methods rely upon one-dimensional or two-dimensional data collection techniques with macro scale stress / strain observations for experimental validation. In order to ascertain the correct load to the failure, a complete understanding of the material failure at the micro-scale is essential. In this work, X-ray computed tomography is employed for the in situ observation of micromechanical failure of the composite material under a compressive load. The observed results are compared and validated with the traditional stress-strain data and finite element analysis. It is observed that the damage in the composite material initiates by delamination which grows as the loading progresses. Moreover, the properties and failure modes are highly dependent on the manufacturing process. By gaining further understanding of the failure modes using these methods, the findings can be utilized in optimizing the design of composite riser structures.


2017 ◽  
Vol 67 (4) ◽  
pp. 420 ◽  
Author(s):  
Subodh Kumar Nirala ◽  
Sarath Shankar ◽  
Dhanalakshmi Sathishkumar ◽  
V. Kavivalluvan ◽  
P. Sivakumar

<p class="p1">Changing circumstances across the world require armored fighting vehicle (AFV) of a country to be more agile, easily manoeuverable and transportable besides other key requirements like firepower and protection. Therefore, the AFV should be as light as possible. The use of conventional materials and techniques do not fulfill the requirement of light weight AFV. The composite materials having high specific modulus, specific strength and directional properties are the alternative substitution for reducing the weight. A customized design approach with proper selection of composite material is essential to make AFV components with required properties at lower weight as compared to the traditional approach. Special properties like resistance to moisture, solvents, UV degradation etc. could be imparted to the composite components by the use of proper additives or fillers. This paper deals with the development of dynamic members like road wheel, top roller and axle arm, whose count is always more in any AFVs, using carbon-epoxy composite material. The details of composite materials used and the manufacturing processes adopted are briefly discussed. The static load test carried out to assess the structural integrity as well as non-destructive tests (NDT) performed to detect the defects are also dealt in detail. Preliminary Finite Element Analysis and Multi-body Dynamic Analysis have also been discussed. These analyses have been done mainly to understand the sustainability and performance of the components developed under the given loading conditions.</p>


2020 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Atyaksheva ◽  
Yermek Sarsikeyev ◽  
Anastasia Atyaksheva ◽  
Olga Galtseva ◽  
Alexander Rogachev

Aims:: The main goals of this research are exploration of energy-efficient building materials when replacing natural materials with industrial waste and development of the theory and practice of obtaining light and ultra-light gravel materials based on mineral binders and waste dump ash and slag mixtures of hydraulic removal. Background.: Experimental data on the conditions of formation of gravel materials containing hollow aluminum and silica microsphere with opportunity of receipt of optimum structure and properties depending on humidity with the using of various binders are presented in this article. This article dwells on the scientific study of opportunity physical-mechanical properties of composite materials optimization are considered. Objective.: Composite material contains hollow aluminum and silica microsphere. Method.: The study is based on the application of the method of separation of power and heat engineering functions. The method is based on the use of the factor structure optimality, which takes into account the primary and secondary stress fields of the structural gravel material. This indicates the possibility of obtaining gravel material with the most uniform distribution of nano - and microparticles in the gravel material and the formation of stable matrices with minimization of stress concentrations. Experiments show that the thickness of the cement shell, which performs power functions, is directly related to the size of the raw granules. At the same time, the thickness of the cement crust, regardless of the type of binder, with increasing moisture content has a higher rate of formation for granules of larger diameter. Results.: The conditions for the formation of gravel composite materials containing a hollow aluminosilicate microsphere are studied. The optimal structure and properties of the gravel composite material were obtained. The dependence of the strength function on humidity and the type of binder has been investigated. The optimal size and shape of binary form of gravel material containing a hollow aluminosilicate microsphere with a minimum thickness of a cement shell and a maximum strength function was obtained. Conclusion.: Received structure allows to separate power and heat engineering functions in material and to minimize the content of the excited environment centers.


Author(s):  
Jiyuan Fan ◽  
Chengkun Xiao ◽  
Jinlin Mei ◽  
Cong Liu ◽  
Aijun Duan ◽  
...  

CoMo series catalysts based on ZSM-22/PHTS (ZP) composite materials with different SiO2/Al2O3 molar ratios were prepared via the impregnation method. The properties of the ZP material and the corresponding catalysts...


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 145
Author(s):  
Lesław Kyzioł ◽  
Katarzyna Panasiuk ◽  
Grzegorz Hajdukiewicz ◽  
Krzysztof Dudzik

Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure.


Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 178
Author(s):  
Valerio Acanfora ◽  
Roberto Petillo ◽  
Salvatore Incognito ◽  
Gerardo Mario Mirra ◽  
Aniello Riccio

This work provides a feasibility and effectiveness analysis, through numerical investigation, of metal replacement of primary components with composite material for an executive aircraft wing. In particular, benefits and disadvantages of replacing metal, usually adopted to manufacture this structural component, with composite material are explored. To accomplish this task, a detailed FEM numerical model of the composite aircraft wing was deployed by taking into account process constraints related to Liquid Resin Infusion, which was selected as the preferred manufacturing technique to fabricate the wing. We obtained a geometric and material layup definition for the CFRP components of the wing, which demonstrated that the replacement of the metal elements with composite materials did not affect the structural performance and can guarantee a substantial advantage for the structure in terms of weight reduction when compared to the equivalent metallic configuration, even for existing executive wing configurations.


Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 81
Author(s):  
Atif Zahid ◽  
Faisal Khan ◽  
Naseer Ahmad ◽  
Irfan Sami ◽  
Wasiq Ullah ◽  
...  

A dual mover yokeless multi-tooth (DMYMT) permanent magnet flux switching motor (PM-FSM) design is presented in this article for ropeless elevator applications. The excitation sources, including a field winding and permanent magnet, are on the short mover in the proposed design structure, whereas the stator is a simple slotted iron core, thus reducing the vertical transportation system cost. The operational principle of the proposed DMYMT in PM-FSM is introduced. The proposed dual mover yokeless multi-tooth Permanent Magnet Flux Switching Motor is analyzed and compared for various performance parameters in a Finite Element Analysis package. The proposed machine has high thrust force and cost-effectiveness compared to conventional dual permanent magnet motor. Finally, this paper also develops an analytical model for the proposed structure, validated by comparing it with Finite Element Analysis simulation results. Results show good agreement between analytical prediction and Finite Element Analysis results.


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