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1.
A test fixture, developed for evaluating the preand postbuckling response of simply supported, nearly flat, rectangular corrugated
board panels subjected to edge compression is evaluated. The test fixture enables loading of panels into the postbuckling
regime until collapse. The shadowmoiré method verified that buckling in the first mode occurred, and that there was symmetry
of the adge-boundary conditions. Through an iterative regression model, experimental curves of load versus out-of-plane displacement
for isotropic panels were fitted to an equation governing the nonlinear postbuckling response. This method provides the critical
buckling load, a postbuckling parameter and the amplitude of initial imperfection of the panel. Comparison with analytical
results revealed that simply supported boundary conditions were closely achieved. Examination of compressively loaded corrugated
board panels showed that collapse occurred due to compressive failures of the facings in the highly stressed edge regions
without severe influence from stress concentrations at load introduction and edge supports. 相似文献
2.
Thermomechanical Postbuckling of Imperfect Moderately Thick Plates on Nonlinear Elastic Foundations*
Hui-Shen Shen 《基于设计的结构力学与机械力学》2013,41(4):513-530
ABSTRACT A postbuckling analysis is presented for a moderately thick rectangular plate subjected to combined axial compression and uniform temperature loading, and resting on a softening nonlinear elastic foundation. The cases of (1) thermal postbuckling of initially compressed plates and (2) compressive post-buckling of initially heated plates are considered. The initial geometrical imperfections of the plates are taken into account. Formulations are based on Reissner-Mindlin plate theory, considering first-order shear deformation effects, and including plate-foundation interaction and thermal effects. The analysis uses a deflection-type perturbation technique to determine buckling loads and postbuckling equilibrium paths. Numerical examples include the performance of perfect and imperfect, moderately thick plates resting on softening nonlinear elastic foundations. Typical results are presented in dimensionless graphical form. 相似文献
3.
Christian Mittelstedt Henrike Erdmann Kai-Uwe Schröder 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(10):1409-1426
In this paper, the postbuckling behavior of rectangular orthotropic laminated composite plates with initial imperfections
under inplane shear load is investigated in a closed-form analytical manner. The plates under consideration are assumed to
be infinitely long in the longitudinal direction. At the longitudinal edges, two different sets of boundary conditions are
considered, specifically 1) simply supported edges and 2) fully clamped edges. Using Timoshenko-type shape functions for both
the initial bifurcational buckling analysis and the subsequent Marguerre-type postbuckling studies, closed-form analytical
solutions for the buckling loads and for the postbuckling state variables are derived. A comparison with geometrically non-linear
finite element computations shows that the derived analysis approaches are suitable for postbuckling studies in load ranges
not too far beyond bifurcational buckling as they are currently relevant for e.g., composite airframe structural analysis
and design. Due to their strictly closed-form analytical nature, the presented analysis methods can be used conveniently in
engineering practice for all application purposes where computational time is a crucial factor, especially for preliminary
analysis and design or optimization procedures. 相似文献
4.
C.A. Featherston 《International Journal of Non》2003,38(2):225-238
The initial buckling load of curved panels under compressive loads is substantially reduced by the existence of imperfections, in particular geometric imperfections. It is therefore essential that these imperfections are considered in analysing components which incorporate such panels in order to accurately predict their buckling behaviour. Finite element analysis allows fully non-linear analysis of shells containing geometric imperfections, however, to obtain accurate results information is required on the exact size and shape of the imperfection to be modelled. In most cases this data is not available. It is therefore generally recommended that the imperfections are modelled on the first eigenmode and have an amplitude selected according to the manufacturing procedure. This paper presents the effects of varying imperfection shape and amplitude on the buckling and postbuckling behaviour of one specific case, a curved panel under combined shear and compression, to test the accuracy of such recommendations. 相似文献
5.
Shen Huishen 《应用数学和力学(英文版)》1997,18(12):1137-1152
Kármán-type nonlinear large deflection equations are derived occnrding to the Reddy’s higher-order shear deformation plate theory and used in the thermal postbuckling analysis The effects of initial geometric imperfections of the plate areincluded in the present study which also includes th thermal effects.Simply supported,symmetric cross-ply laminated plates subjected to uniform or nomuniform parabolictemperature distribution are considered. The analysis uses a mixed GalerkinGolerkinperlurbation technique to determine thermal buckling louds and postbucklingequilibrium paths.The effects played by transverse shear deformation plate aspeclraio, total number of plies thermal load ratio and initial geometric imperfections arealso studied. 相似文献
6.
非线性弹性基础上矩形板热后屈曲分析 总被引:1,自引:0,他引:1
给出非线性弹性基础上矩形板在均匀和非均匀(抛物型)热分布作用下的后屈曲分析。采用摄动——Galerkin混合法给出完善和非完善矩形板热屈曲载荷和热后屈曲平衡路径。数值计算结果表明,非线性弹性基础上矩形板具有不稳定的热后屈曲平衡路径,且对初始几何缺陷是敏感的 相似文献
7.
X. Ma J.W. Butterworth G.C. Clifton 《International Journal of Solids and Structures》2008,45(3-4):840-849
Thin, profiled steel sheets forming the skin of concrete-filled composite wall panels and similar members benefit from the unilateral (tensionless) restraint provided by fill of sufficient elastic modulus. This paper investigates the buckling of such skin sheets in panels subjected to compressive or shearing loads. The profiled skins are modelled as infinite, thin orthotropic plates resting on tensionless rigid foundations, allowing the local buckling response to be simulated by the single-wave buckling mode of an unrestrained plate section of appropriate aspect ratio. Solution of the governing differential equations leads to the determination of the plate buckling coefficients. Simplified formulas for the buckling coefficients in terms of the parameters describing the skin sheets are developed and shown to agree well with published results and finite element analyses for particular limiting cases. 相似文献
8.
A thermal postbuckling analysis is presented for a moderately thick rectangular plate subjected to (1) uniform and non-uniform
tent-like temperature loading; and (2) combined axial compression and uniform temperature loading. The initial geometrical
imperfection of plate is taken into account. The formulations are based on the Reissner-Mindlin plate theory considering the
effects of rotary inertia and transverse shear deformation. The analysis uses a deflection-type perturbation technique to
determine the thermal buckling loads and postbuckling equilibrium paths. Numerical examples are presented that relate to the
performances of perfect and imperfect, moderately thick rectangular plates and are compared with the results predicted by
the thin plate theory. 相似文献
9.
Test fixture for eccentricity and stiffness of corrugated board 总被引:1,自引:0,他引:1
M. Renman 《Experimental Mechanics》1996,36(3):262-268
Of particular importance for the mechanical response and load-bearing capacity of corrugated board boxes is the manner in
which load is introduced in the vertical panels through the horizontal flaps and the adjoining creases (folding lines). This
study reports on a test fixture developed to measure the effective eccentricity moment acting on the vertical panels of corrugated
board boxes. The axial compressive response of the creased board can also be measured using the new test fixture. The deformation
mechanism of the board was monitored by visual inspection and photographically recorded and related to the measured eccentricity
moment. The results show that significant eccentricity of the load path exists, which depends on the degree of lateral constraint
and amount of axial deformation in a quite complex manner. The axial compressive response was found to be independent of the
degree of lateral constraint and unsupported length of the specimen, which is evidence for the majority of the axial deformation
occurring in the creased region. Photographic recording of the deformation mechanism of the creased region during compressive
loading verified that the board is loaded unevenly as evidenced by kink zone formations appearing at opposite sides at different
axial deformation levels. 相似文献
10.
Thermo-piezoelectric effects on the postbuckling of axially-loaded hybrid laminated cylindrical panels 总被引:1,自引:0,他引:1
沈惠申 《应用数学和力学(英文版)》2004,25(1):24-38
IntroductionCompositelaminatedcylindricalpanelhasbeenusedextensivelyasastructuralconfiguration,mainlyintheaerospaceindustry .Oneoftherecentadvancesinmaterialandstructuralengineeringisinthefieldofsmartstructureswhichincorporatesadaptivematerials.Bytakingadvantageofthedirectandconversepiezoelectriceffects,piezoelectriccompositestructurescancombinethetraditionalperformanceadvantagesofcompositelaminatesalongwiththeinherentcapabilityofpiezoelectricmaterialstoadapttotheircurrentenvironment.Therefore… 相似文献
11.
《International Journal of Solids and Structures》2003,40(15):3869-3892
In this paper, we examine the postbuckling behavior of functionally graded material FGM rectangular plates that are integrated with surface-bonded piezoelectric actuators and are subjected to the combined action of uniform temperature change, in-plane forces, and constant applied actuator voltage. A Galerkin-differential quadrature iteration algorithm is proposed for solution of the non-linear partial differential governing equations. To account for the transverse shear strains, the Reddy higher-order shear deformation plate theory is employed. The bifurcation-type thermo-mechanical buckling of fully clamped plates, and the postbuckling behavior of plates with more general boundary conditions subject to various thermo-electro-mechanical loads, are discussed in detail. Parametric studies are also undertaken, and show the effects of applied actuator voltage, in-plane forces, volume fraction exponents, temperature change, and the character of boundary conditions on the buckling and postbuckling characteristics of the plates. 相似文献
12.
This paper presents a study on the postbuckling responses of shear deformable laminated plates resting on a tensionless foundation of the Pasternak-type and subjected to combined axial and thermal loads. Two different postbuckling cases are considered, namely (1) the compressive postbuckling of initially heated plates and (2) the thermal postbuckling of initially compressed plates. The postbuckling analysis of laminated plates is based on the higher order shear deformation plate theory with a von Kármán-type of kinematic non-linearity. It is assumed that the foundation reacts in compression only. The thermal effects are also included and the material properties are assumed to be temperature dependent. The initial geometric imperfection of the plates is taken into account. The analysis uses a two-step perturbation technique to determine the postbuckling response of the plates. An iterative scheme is developed to obtain numerical results without using any assumption on the shape of the contact region. Numerical solutions are presented in tabular and graphical forms to study the postbuckling behavior of antisymmetric angle-ply and symmetric cross-ply laminated plates resting on tensionless elastic foundations of the Pasternak-type, from which results for conventional elastic foundations are obtained as comparators. The results reveal that the unilateral constraint has a significant effect on the postbuckling response of the plates subjected to combined axial and thermal loads when the foundation stiffness is sufficiently large. The results also confirm that the postbuckling responses are significantly influenced by temperature dependency and initial membrane stress as well as initial thermal stress. 相似文献
13.
The elasto-plastic dynamic buckling and postbuckling phenomena ofsquare plates subjected to in-plane solid-fluid slamming are investigated.According tothe plate's response,the critical criteria for dynamic buckling,dynamic plasticity andplasti(?)collapse are defined,and the corresponding critical impulses are presented.Meanwhile,dynamic buckling modes and collapse models are observed.The effects ofdifferent boundary conditions and loading histories on the properties of buckling andpostbuckling are discussed. 相似文献
14.
《International Journal of Solids and Structures》2004,41(5-6):1519-1538
A theoretical framework for analyzing the pre- and postbuckling response of composite laminates and plates with piezoactuators and sensors is presented. The mechanics include nonlinear effects due to large rotations and stress stiffening, and are incorporated into a coupled mixed-field piezoelectric laminate theory. Using the previous mechanics, a nonlinear finite element method and an incremental-iterative solution are formulated for the analysis of nonlinear adaptive plate structures subject to in-plane electromechanical loading. A novel eight-node nonlinear plate finite element is also developed. Evaluation cases predict the buckling and postbuckling response of adaptive composite beams and plates with piezoelectric actuators and sensors. The case of piezoelectric buckling and postbuckling induced by the actuators is addressed and quantified. Finally, the possibility to actively mitigate the mechanical buckling and postbuckling response of adaptive piezocomposite plates is illustrated. 相似文献
15.
16.
本文基于弹性板理论和夹层板理论对二级层级褶皱结构失效模式进行了分析。通过对基本构件进行受力分析得到了载荷与结构变形之间的关系。根据6种失效模式的定义,从极限载荷或极限应力角度出发,分析了在压缩载荷和剪切载荷工况下的各种失效模式,给出了结构单胞对应的等效正应力和等效切应力表达式。由最小失效强度得到了各失效模式之间的占优关系,并构建了失效机理图来阐释这一机制。最后通过与有限元分析结果比较,分析了本文公式的精度,与数值解吻合较好。 相似文献
17.
18.
The buckling, postbuckling and postbuckled vibration behaviour of composite skew plates subjected to nonuniform inplane loadings are presented here. The skew plate is modelled using first order shear deformation theory accounting for von-Kármán geometric nonlinearity and initial geometric imperfections. The different types of nonuniform loads that have been considered in this study are concentrated load, partial load and parabolic load. The explicit analytical expressions for prebuckling stress distributions within composite skew plate subjected to three different types of nonuniform inplane loadings are developed by solving plane elasticity problem using Airy's stress function approach. It is observed that the inplane normal stress distributions within the skew plate due to above nonuniform loadings do not become uniform even at mid-section. The generalized differential quadrature (GDQ) method is used to solve the nonlinear governing partial differential equations. It is observed that the postbuckled load carrying capacity of skew plate under concentrated loading is the lowest compared to other nonuniform and uniform loadings. 相似文献
19.
B. Wu 《Archive of Applied Mechanics (Ingenieur Archiv)》1998,68(5):342-351
Summary The postbuckling behavior of an elastic column with spring supports of equal stiffness of extensional type at both clamped
ends is studied. Attention is focused on those of spring stiffnesses near the critical value at which, under axial load, the
column becomes critical with respect to two buckling modes simultaneously. By using the Liapunov-Schmidt-Koiter approach,
we show that there are precisely two secondary bifurcation points on each primary postbuckling state for the spring stiffness
greater than the critical value. The bifurcation takes place at one of the two least buckling loads. The corresponding secondary
postbuckling states connect all the secondary bifurcation points in a loop. For the spring stiffness less than the critical
value, no secondary bifurcation occurs. Asymptotic expansions of the primary and secondary postbuckling states are constructed.
The stability analysis indicates that the primary postbuckling state for the spring stiffness greater than the critical value
is bifurcating from the first buckling load and becomes unstable from a stable state via the secondary bifurcation, i.e.,
secondary buckling occurs.
Received 22 April 1997; accepted for publication 22 December 1997 相似文献
20.
C.S. Lopes P.P. Camanho Z. Gürdal B.F. Tatting 《International Journal of Solids and Structures》2007,44(25-26):8493-8516
The past developments on tow-placement technology led to the production of machines capable of controlling fibre tows individually and placing them onto the surface of a laminate with curvilinear topology. Due to the variation of properties along their surface, such structures are termed variable-stiffness composite panels.In previous experimental research tow-steered panels have shown increased buckling load capacity as compared with traditional straight-fibre laminates. Also, numerical analyses by the authors showed that first-ply failure occurs at a significant higher load level. The focus of this paper is to extend those analyses into the postbuckling progressive damage behaviour and final structural failure due to accumulation of fibre and matrix damage. A user-developed continuum damage model implemented in the finite element code ABAQUS® is employed in the simulation of damage initiation and material stiffness degradation.In order to correctly predict the buckling loads of tow-steered panels under compression, it is of crucial importance to take into account the residual thermal stresses resulting from the curing process. Final failure of tow-steered panels in postbuckling is predicted to within 10% difference of the experimental results. Curvilinear-fibre panels have up to 56% higher strength than straight-fibre laminates and damage initiation is also remarkably postponed. Tow-steered designs also show more tolerance to central holes than traditional laminates. 相似文献