Evaluating the potential use of composites in ship shafting 3. Efficient design of the intermediate shaft of ship shafting

This report examines the problems associated with the design of a composite intermediate shaft for a ship shaftline. A comparison is made between shafts of carbon- and glass-fiber-reinforced plastics made by winding with different laws governing the change in winding angle through the thickness of the shaft. An analysis and comparison of results obtained for a specific example show that the use of a composite significantly reduces the weight and stiffness of the shaft compared to steel shafts and thus appreciably reduces all of the additional loads on the bearings and other shafts.See [2] for Report No. 2.Institute of Polymer Mechanics, Latvian Academy of Sciences (Riga, LV-1006 Latvia). Translated from Mekhanika Kompozitnykh Materialov, No. 1, pp. 66–81, January–February, 1997.     

Investigation of the principal dense-winding conditions for wound glass-reinforced plastic pipe

The dense-winding conditions have been found for glass-reinforced plastic pipe wound simultaneously with a large number of strands [conditions (15), (17), and (18)] and relations have been obtained for calculating the winding mechanism kinematics. Kinematic equations have been derived for dense winding by displacement of the strands in the pipe cross section, along the pipe axis, and in both directions at once.Glass-Reinforced Plastics Division of the All-Union Lenin Electrical Engineering Institute, Khar'kov. Translated from Mekhanika Polimerov, No. 6, pp. 1057–1064, November–December, 1970.     

Calculation of the residual stresses in wound glass-reinforced plastics

The effect of the winding and polymerization conditions on the residual stress distribution in wound glass-reinforced plastic cylinders is subjected to a numerical analysis. The calculations are based on the method proposed in [1]. The computer data are examined and the theoretical and experimental results compared.Moscow Power Engineering Institute. Translated from Mekhanika Polimerov, No. 6, pp. 1026–1030, November–December, 1970.     

A model for taking into account the nonlinearity of properties of a semifinished product in the force analysis of the winding of composite materials

Conclusions 1. The proposed method of accounting for the nonlinearity of properties of a semifinished product by a piecewise-linear approximation of its stress—strain diagram greatly refines the calculation of stresses induced during the process of winding a product.2. A numerical analysis has revealed the ranges of values of the winding parameters where replacing the nonlinear model by simpler linear models for the calculation is appropriate.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 2, pp. 231–240, March–April, 1977.     

Algorithmization of the control of the working mechanisms of machines for winding glass-reinforced plastic shells

Conclusions 1. A block diagram has been developed for solving the problem of the algorithmization and programming of the control of multicoordinate winding machines. This reduces the design process to four main steps.2. A general approach to the optimization of the tape-laying process with reference to a formulated quality criterion is presented.3. With this method, even in the design stage precise requirements can be formulated in respect of the working mechanisms and control systems with the object of either maximizing output or minimizing installed power.4. Relations between the TLP and TCP trajectories are obtained for motion of the working mechanisms along approximate trajectories. This problem is solved for the general case, irrespective of the form of the approximation and the type of wound surface.5. The optimum structure of the programmed control system is determined and the necessary coordination of the individual coordinate systems is found for large winding machines.For communication 1, see [1].V. I. Ul'yanov (Lenin) Leningrad Electrical-Engineering Institute. Translated from Mekhanika Polimerov, No. 3, pp. 435–442, May–June, 1978.     

Residual stresses in plastic rings reinforced with glass and manufactured with consolidation of the various layers

The residual stresses in thin-wall plastic rings reinforced with glass and prepared by the method of consolidating the layers in combination with various winding regimes have been studied experimentally. It is shown that variation of the winding regime from one layer to another can change the distribution of the stresses through the thickness of the ring.Moscow Energy Institute. Translated from Mekhanika Polimerov, No. 1, pp. 174–176, January–February, 1972.     

Effect of technological factors on the mechanical reliability of structures made from composites

Research on the effect of technological factors on the strength of reinforced-plastics structures is reviewed. Attention is concentrated on structures in the form of bodies of revolution fabricated by the winding technique. The influence of the winding parameters and the curing regime on the residual stresses is discussed. Data on the variation of the mechanical properties of the resin in the course of the curing process are examined. The contributions of chemical and thermal shrinkage to residual stress formation are compared. Methods of reducing the residual stresses are considered.Presented at the 2nd All-Union Conference on Polymer Mechanics, Riga, November 10–12, 1971.Moscow Power Engineering Institute. Translated from Mekhanika Polimerov, No. 3, pp. 529–540, May–June, 1972.     

Design of Steel-Composite Multirim Cylindrical Flywheels Manufactured by Winding with High Tensioning and <Emphasis Type="Italic">in situ</Emphasis> Curing. 1. Basic Relations

The possibility of using force winding coupled with in situ curing to increase the energy storage capacity of hybrid steel-composite cylindrical flywheels is estimated and analyzed. Relations describing the rotational, thermal, and winding stresses are considered and discussed. These relations are used for a numerical analysis of the stress state and energy capacity of hybrid flywheels in the second part of the paper.__________Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 41, No. 2, pp. 203–224, March–April, 2005.     

Variation of the residual stresses during the fabrication of thick-walled wound glass-reinforced plastic articles

The results of an experimental investigation of the development of the residual stresses in thick-walled glass-reinforced plastic cylinders during the fabrication process are presented. The variation of the stresses from the beginning of winding to removal of the cyclinders from the mandrel is examined.Translated from Mekhanika Polimerov, No. 2, pp. 355–357, March–April, 1974.     

Experimental study of the effect of technological parameters on the residual stresses in thin-walled coiled parts

The effect of the parameters of heat treatment and programmed winding under tension on the residual stresses in thin-walled coiled parts made from glass plastic by the "dry" winding of a heated glass strip on an unheated mandrel is studied experimentally. The effect of the thickness of the parts on the maximum radial residual stresses is considered. A method is proposed for regulating the residual stresses in parts with very thick walls.Translated from Mekhanika Polimerov, No. 1, pp. 75–80, January–February, 1972.     

Analysis of the zonal winding pattern of thin spherical shells

Conclusions 1. A method has been proposed for calculating the zonal pattern of winding thin spherical shells.2. The tested strength of shells wound by the calculated pattern correlates with the theoretical.3. The proposed calculation apparatus makes it possible to calculate winding patterns with any variants of angles and number of zones.4. A zonal pattern in a spherical shell having a connecting pipe of small diameter can give a mean constructional strength which does not exceed 0.39 times the strength of the unidirectional plastic (as against 0.5 in the ideal case for a sphere of bidirectional material), i.e., not more than 78% of the strength of the plastic is realized.5. The bearing ability of a sphere wound by the zonal method is 22% less than that of a long cylinder (with no bottom) made by the same winding method.All-Union Scientific-Research Institute of Aviation Materials, Moscow. Translated from Mekhanika Polimerov, No. 4, pp. 625–631, July–August, 1978.     

Optimal winding of filament-wound reinforced plastic shells designed to resist buckling under external pressure or axial compression

The optimal method of winding the reinforcement of thin cylindrical shells subjected to external pressure or axial loading is investigated. Various types of winding — normal, simple oblique, crossed, and isotropic — are considered. An approximate formula is obtained for the critical external pressure. This formula is used to analyze the possibility of raising the critical load by adopting oblique winding. In the case of axial compression different buckling modes are examined and the optimal winding determined.Central Scientific-Research Institute of Machine Building, Moscow. Translated from Mekhanika Polimerov, Vol. 4, No. 5, pp. 864–875, September–October, 1968.     

Optimal Design of Filament-Wound Composite Pressure Vessels

In this paper, the effect of the width of winding band on the stability of winding pattern is studied. Some key design variables are calculated to optimize the dome geometry. The influence of winding process parameters on the slippage tendency is also considered.__________Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 41, No. 4, pp. 489–498, July–August, 2005.     

Determination of the mechanical characteristics of a glass-reinforced plastic during winding

Problems associated with the determination of the transverse modulus of the material under compression during winding are examined. The rheological characteristics of the material are investigated on the basis of the short-time and long-time creep curves for winding processes conducted at normal and elevated temperatures.Ordzhonikidze Moscow Aviation Institute. Translated from Mekhanika Polimerov, No. 1, pp. 162–164, January–February, 1973.     

Mechanism by which tension on the fibrous filler affects the structure and the strength of wound glass-plastics

Conclusions 1. We have studied how the structure of glass-plastics wound with twisted threads is affected by tension on the fibrous filler. The trend of changes in fiber content and porosity, as well as an increasingly nonuniform distribution of the reinforcing filler over the thickness, has been established.2. The effect of a nonuniform filler distribution over the thickness on the tensile strength has been evaluated. The calculated and the experimental curve of strength as a function of the tension have been compared, the former taking into account variable porosity, fiber content, and nonuniformity of fiber distribution over the thickness.3. It has been demonstrated that the change in the strength characteristics of a wound glass-plastic as a function of the tension on the reinforcing filler during winding is due to a combined complex effect of such factors as the overall fiber content and porosity, a nonuniform fiber distribution over the thickness, the fiber orientation, and the degree of mechanical damage in threads due to their interaction with the active components of the winding machine.Report presented at the Third All-Union Conference on Polymer Mechanics. Riga, November 10–12, 1976.Translated from Mekhanika Polimerov, No. 3, pp. 439–444, May–June, 1977.     

Optimization of the axial stability of equal-strength reinforced cylindrical pressure vessels

The class of reinforced cylindrical shells obtained by spiral winding with reinforcing ring or longitudinal layers is considered. The structure of the shells is optimal with respect to internal pressure. The reinforcement angle is selected so as to maximize the critical axial load.Translated from Mekhanika Polimerov, No. 6, pp. 1123–1126, November–December, 1973.     

Analysis of the technological stresses in wound components made out of composites during the whole duration of the preparation process

Conclusions The application of a discrete winding scheme and the relationships of the theory of filtration consolidation and the theory of unstable viscoelastic media to the calculation of the technological stresses allows one to take account of the most important technological factors and to describe the overall process involved in the preparation of wound components from laminar composites. The power winding stage and the nonisothermal heat-treatment stage make the greatest contribution to the magnitude of the technological stresses.Translated from Mekhanika Kompozitnykh Materialov, No. 3, pp. 500–508, May–June, 1980.     

Winding glass-reinforced plastic rings under programmed tension

The strength, stiffness, and initial stresses of glass-reinforced plastic rings wound under variable tension in accordance with five different programs are considered. The relative thickness of the rings was 0.15–0.20. It is shown that the law of variation of the tension on the tape during winding has an important effect on the investigated parameter.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 2, pp. 361–364, March–April, 1971.     

Effect of material structure on the stability of a laminated-plastic cylindrical shell

A compact equation is proposed for analyzing the stability of layered shells in relation to their structure. The case of a shell with split longitudinal-transverse winding subjected to hydrostatic pressure is investigated.Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Mekhanika Polimerov, No. 1, pp. 147–150, January–February, 1971.     

Experimental investigation of forces affecting the formation of fiberglass plastic structures by winding

A method is suggested for the investigation of pressure occurring in the winding of glass fiber plastic coils, at tensions of the glass reinforcement used in practice.Translated from Mekhanika Polimerov, No. 5, pp. 938–940, September–October, 1972.