共查询到15条相似文献,搜索用时 28 毫秒
1.
G. Teters 《Mechanics of Composite Materials》2006,42(4):347-352
The multicriteria optimization of the structure and geometry of a laminated cylindrical shell under the action of external
pressure and longitudinal thermal stresses is considered. From the known monolayer properties of the composite and the given
values of variable structural and geometric parameters, the thermoelastic properties of the anisotropic layered composite
are determined. The criteria to be optimized — the critical external pressure and thermal stresses — depend on two variable
parameters and temperature. In the space of optimization criteria, the domain of allowable solutions and the Pareto-optimal
subdomain are found.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 4, pp. 495–502, July–August, 2006. 相似文献
2.
Multicriteria optimization of a composite cylindrical shell subjected to thermal and dynamic actions 总被引:1,自引:0,他引:1
Multicriteria optimization of the structure and geometry of a laminated anisotropic composite shell subjected to thermal and dynamic actions is considered. From the known properties of monolayers and the given values of variable structural and geometric parameters, the thermoelastic properties of the layered anisotropic composite are determined. The criteria to be optimized—the natural frequency and the thermal stresses—depend on two variable design parameters, stochastic properties of the composite, and temperature. In the space of the optimization criteria, the domain of allowable solutions and the Pareto-optimal region are found.Translated from Mekhanika Kompozitnykh Materialov, Vol. 40, No. 6, pp. 753–760, November–December, 2004. 相似文献
3.
G. Teters 《Mechanics of Composite Materials》2007,43(1):59-62
The multicriteria optimization of the structure and geometry of a laminated anisotropic composite plate subjected to thermal
and shear loading is considered. From the known properties of the monolayer and given values of variable structural parameters,
the thermoelastic properties of the layered composite are determined. The optimization criteria — the critical shear load
and the longitudinal thermal stresses — depend on two variable design parameters of composite properties and temperature.
In the space of optimization criteria, the domain of allowable solutions and the Pareto-optimal subregion are found.
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Translated from Mekhanika Kompozitnykh Materialov, Vol. 43, No. 1, pp. 85–92, January–February, 2007. 相似文献
4.
Compromise optimization of a rectangular composite plate subjected to biaxial thermal loading and buckling under the action of shear 总被引:1,自引:1,他引:0
G. Teters 《Mechanics of Composite Materials》2008,44(4):325-330
The compromise optimization of the structure and geometry of a laminated anisotropic composite plate subjected to biaxial
thermal shear loading is considered. From the known properties of the monolayer and given values of a variable structural
parameter, the thermoelastic properties of the layered composite are determined. The optimization criteria — the critical
shear load and the longitudinal and transverse thermal stresses — depend on two variable design parameters of composite properties
and temperature. In the space of optimization criteria, the domain of allowable solutions and the Pareto-optimal subregion
are found.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 44, No. 4, pp. 471–478, July–August, 2008. 相似文献
5.
V. N. Paimushin V. A. Ivanov S. A. Lukankin A. A. Bushkov 《Mechanics of Composite Materials》2004,40(6):461-472
A solution to the problem on the stability according to the flexural buckling mode is given for a cylindrical sandwich shell with a transversely soft core of arbitrary thickness. The shell is under the action of a temperature field inhomogeneous across the thickness, and its end faces are fastened in such a way (in the axial direction, the face sections of the external layer are fixed, but of the internal one are free) that an inhomogeneous subcritical stress-strain state arises in the shell across the thickness of its layers. It is shown that, under such conditions, the buckling mode of the shell is mixed flexural. To reveal and investigate this mode, equations of subcritical equilibrium and stability of a corresponding degree of accuracy are needed.Translated from Mekhanika Kompozitnykh Materialov, Vol. 40, No. 6, pp. 715–730, November–December, 2004. 相似文献
6.
Based on the generalized Timoshenko-type shell theory, a numerical-analytical procedure for determining contact stresses from
the interaction between a cylindrical composite shell and rigid bandings is proposed. Specific cases of loading and contact
interaction (ideal contact through an adhesive interlayer) are considered. The contact problems are reduced to the solution
of a Fredholm integral equation of the second-kind. A calculation analysis is performed.
Translated from Mekhanika Kompozitnykh Materialov, Vol. 35, No. 1, pp. 109–120, January–February, 2000. 相似文献
7.
Zhi-Min Li 《Mechanics of Composite Materials》2007,43(6):535-560
A postbuckling analysis is presented for a shear-deformable anisotropic laminated cylindrical shell of finite length subjected
to external pressure in thermal environments. The material properties are expressed as linear functions of temperature. The
governing equations are based on Reddy’s higher-order shear-deformation shell theory with the von Karman-Donnell-type kinematic
nonlinearity. The nonlinear prebuckling deformations and initial geometric imperfections of the shell are both taken into
account. The boundary-layer theory of shell buckling, which includes the effects of nonlinear prebuckling deformations, large
deflections in the postbuckling region, and the initial geometric imperfections of the shell, is extended to the case of shear-deformable
anisotropic laminated cylindrical shells under lateral or hydrostatic pressure in thermal environments. The singular perturbation
technique is employed to determine the interactive buckling loads and postbuckling equilibrium paths. The results obtained
show that the variation in temperature, layer setting, and the geometric parameters of such shells have a significant influence
on their buckling load and postbuckling behavior.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 43, No. 6, pp. 789–822, November–December, 2007. 相似文献
8.
G. Teters 《Mechanics of Composite Materials》2005,41(5):461-466
Multicriteria optimization of the structure and geometry of a laminated anisotropic composite plate subjected to the thermal
and biaxial action is considered. From known properties of the monolayer and the given values of variable structural parameters,
the thermoelastic properties of the layered composite are determined. The criteria to be optimized—the transverse critical
load and the longitudinal thermal stresses—depend on two variable design parameters of composite properties and temperature.
In the space of the optimization criteria, the domain of allowable solutions and the Pareto-optimal subdomain are found.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 5, pp. 683–690, September–October, 2005. 相似文献
9.
Stress state of a composite shell with a sizable opening 总被引:1,自引:0,他引:1
The stress-strain state of a nonshallow cylindrical shell of a composite material is investigated. The shell is weakened by a circular hole and loaded with internal pressure. For solving the problem, the variational-difference method is used. The calculations are carried out for an orthotropic shell with a sizable hole, with account of the reduced shear stiffness of the material.Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 1, pp. 49–56, January–February, 2005. 相似文献
10.
We consider the plane-strain buckling of a cylindrical shellof arbitrary thickness which is made of a Varga material andis subjected to an external hydrostatic pressure on its outersurface. The WKB method is used to solve the eigenvalue problemthat results from the linear bifurcation analysis. We show thatthe circular cross-section buckles into a non-circular shapeat a value of µ1 which depends on A1/A2 and a mode number,where A1 and A2 are the undeformed inner and outer radii, andµ1 is the ratio of the deformed inner radius to A1. Inthe large mode number limit, we find that the dependence ofµ1 on A1/A2 has a boundary layer structure: it is constantover almost the entire region of 0 < A1/A2 < 1 and decreasessharply from this constant value to unity as A1/A2 tends tounity. Our asymptotic results for A1 1 = O(1) and A1 1 = O(1/n) are shown to agree with the numerical resultsobtained by using the compound matrix method. 相似文献
11.
V. N. Paimushin V. A. Ivanov S. A. Lukankin A. A. Bushkov A. E. Vyalkov 《Mechanics of Composite Materials》2005,41(1):23-32
Equations are set up for describing, in a correct statement and with an accuracy sufficient in actual practice, the shear buckling modes (BMs) of cylindrical sandwich shells with a transversely soft core of arbitrary thickness. Based on them, solutions are obtained to a number of problems on the buckling instability according to shear modes under some force and thermal loadings. It is found that the BMs occur in the shell along the circumferential and axial directions if, in the precritical state, a normal compressive stress arises in the transverse direction. It is shown that this condition is fulfilled in the following cases: in axial tension of the shell with unequal forces applied to the end faces of bearing layers (the parameter of critical load is maximum if the tensile forces are equal); under external (internal) pressure; on cooling the outer and heating the inner layers. The results obtained are presented in the form of simple analytical formulas for determining the corresponding critical parameters of the force and thermal actions.Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 1, pp. 37–48, January–February, 2005. 相似文献
12.
13.
In this paper, we consider convex composite optimization problems on Riemannian manifolds, and discuss the semi-local convergence of the Gauss-Newton method with quasi-regular initial point and under the majorant condition. As special cases, we also discuss the convergence of the sequence generated by the Gauss-Newton method under Lipschitz-type condition, or under γ-condition. 相似文献
14.
V. P. Korkhov Ye. A. Faitelson T. I. Glaskova Yu. O. Jansons 《Mechanics of Composite Materials》2005,41(4):365-370
Properties of a model composite based on an ED-22 epoxy binder, cured with polyprophylene polyamine, and disperse LiF crystals as a filler were investigated by the methods of dilatometry and X-ray diffractometry. It was established that the density of cross-links of the epoxy binder in the interphase layer was lower than in a block specimen. Therefore, the thermal expansion of the composite on heating to 120°C, in terms of that of the binder, grew significantly with the degree of filling ϕ, and the water uptake also increased at the initial stage. The presence of absorbed water led to considerable changes in the structure and properties of the composite interphase: the binder became more cross-linked, its structural ordering decreased, the thermal expansion at heating diminished by a factor of 3. 7 (at ϕ = 50%), and the glass-transition temperature increased. As a result of long-term action of moisture, changes in the internal stresses had an extreme character.__________Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 4, pp. 535–544, July–August, 2005. 相似文献
15.
In the area of broad-band antenna array signal processing, the global minimum of a quadratic equality constrained quadratic cost minimization problem is often required. The problem posed is usually characterized by a large optimization space (around 50–90 tuples), a large number of linear equality constraints, and a few quadratic equality constraints each having very low rank quadratic constraint matrices. Two main difficulties arise in this class of problem. Firstly, the feasibility region is nonconvex and multiple local minima abound. This makes conventional numerical search techniques unattractive as they are unable to locate the global optimum consistently (unless a finite search area is specified). Secondly, the large optimization space makes the use of decision-method algorithms for the theory of the reals unattractive. This is because these algorithms involve the solution of the roots of univariate polynomials of order to the square of the optimization space. In this paper we present a new algorithm which exploits the structure of the constraints to reduce the optimization space to a more manageable size. The new algorithm relies on linear-algebra concepts, basic optimization theory, and a multivariate polynomial root-solving tool often used by decision-method algorithms.This research was supported by the Australian Research Council and the Corporative Research Centre for Broadband Telecommunications and Networking. 相似文献