Hybrid method for analysis of thermally stressed plates
About: This article is published in Journal of Sound and Vibration.The article was published on 1984-05-01. It has received 9 citations till now.
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TL;DR: In this article, two longer test piles and an integrated monitoring system were installed in the landslide to better understand the failure mode of the landslide and to measure the deformation characteristics of landslide-stabilizing pile system.
Abstract: Landslides often occur within the reservoir area behind dams. In China, a common strategy for stabilizing these landslides is to install large piles through the landslide and into the stable ground below. The piles interact with the landslide and constitute a landslide-stabilizing pile system. The deformation of this system under the reservoir operation is more complicated than the deformation of the landslide itself. Understanding the behaviour of this system is very important to the long-term safety of landslides stabilized with piles in reservoirs. The Majiagou landslide, which was selected as a case study, was triggered by the first impoundment of the reservoir behind the Three Gorges dam. A row of anti-slide piles was installed in the landslide in 2007, but monitoring results found these were ineffective at stabilizing the landslide. Subsequently, in 2011, two longer test piles and an integrated monitoring system were installed in the landslide to better understand the failure mode of the landslide and to measure the deformation characteristics of the landslide-stabilizing pile system. Monitoring results show that the Majiagou landslide is a translational landslide with three slip surfaces. The test piles provided local resistance and partially slowed down the sliding mass behind the piles, and the landslide deformation response to external factors decreased for a time. However, after 2 years, the deformation of the landslide-stabilizing pile system reverted to seasonal stepwise cumulative displacements influenced by cycles of reservoir drawdown and rainfall. The monitoring results provide fundamental data for evaluating the long-term performance of anti-slide piles and for assessing long-term stability of the stabilized landslide under the reservoir operation.
78 citations
Cites background from "Hybrid method for analysis of therm..."
...For landslide-stabilizing pile systems, research has focused on two aspects: (1) the interaction mechanisms between the piles and the sliding mass, considering the pile spacing, pile embedment length, and the rock mass structure of the embedded layer (Kourkoulis et al. 2011; Guo 2015; Li et al. 2016; Sharafi and Sojoudi 2016) and (2) the evaluation of the effectiveness of antislide piles under heavy rainfall and reservoir water level fluctuation (Frank and Pouget 2008; Smethurst and Powrie 2007; Wei et al....
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TL;DR: In this article, a study on vibration and acoustic radiation characters of an isotropic rectangular thin plate under thermal environments is presented, which is assumed that thermal loads caused by thermal environments just change the structure stress state.
Abstract: A study on vibration and acoustic radiation characters of an isotropic rectangular thin plate under thermal environments is presented in this paper. It is assumed that thermal loads caused by thermal environments just change the structure stress state. Thermal stresses induced by uniform temperature rise of the plate are determined with the thermo-elastic theory. Then the stress state is used in the following dynamic analysis as a pre-stressed factor. It is observed that thermal loads influence the natural frequencies evidently, especially the fundamental natural frequency. The order of mode shapes stays the same. Dynamic response peaks float to lower frequency range with the increment of structure temperature. Acoustic radiation efficiency of the plate subjected to thermal loads decreases in the mid-frequency band. For validation, numerical simulations are also carried out. It can be found that the combined approach of finite element method (FEM) and boundary element method (BEM) is more appropriate for radiation problems.
58 citations
TL;DR: Experiments to investigate the vibration and acoustic response characteristics of a clamped rectangular aluminum plate in thermal environments indicated that the initial deflection has a great influence on the natural vibration of the heated plate.
Abstract: Experiments were performed to investigate the vibration and acoustic response characteristics of a clamped rectangular aluminum plate in thermal environments. Modal tests were carried out to study the influence of thermal environment on natural vibration. With the increment of structural temperature, natural frequencies of the plate decrease obviously. Mode shape interchange was observed for the modes with frequencies very close to each other. The thermally induced softening effect has unequal influences on the plate along the two in-plane directions. Numerical methods were also employed to study the experimental phenomena. Calculated results indicated that the initial deflection has a great influence on the natural vibration of the heated plate. Even a slight curvature can reduce the thermally induced softening effect obviously. Dynamic response tests were carried out under acoustic and mechanical excitations, and the measured results indicate that the variation in damping determines the response amplitudes at resonant peaks in the test.
56 citations
TL;DR: In this article, a set of double sinusoidal mode shape functions for fully clamped boundaries is used to describe the displacement distribution of a clamped rectangular thin plate in thermal environments.
Abstract: This work presents an investigation of vibration and acoustic response characters of a clamped rectangular thin plate in thermal environments. The general form of governing equation of plate flexural vibration with considering thermal loads is established, and the influence of uniform temperature change on response characters is studied in detail. A set of double sinusoidal mode shape functions for fully clamped boundaries is used to describe the displacement distribution. The governing equation is solved with Fourier series expansion to discuss the natural vibration and dynamic responses of a clamped plate in thermal environments. Accordingly, acoustic radiation characteristics are obtained based on Rayleigh integral. Results show that natural frequencies decrease with the increment of plate temperature, and the first natural frequency is much more sensitive to thermal environment changes. Response curves of plate vibration and radiated sound power shift toward lower frequency range, and the response amp...
43 citations
Cites background from "Hybrid method for analysis of therm..."
...Ganesan and Dhotarad (1984) studied the vibration responses of thermally stressed plates with numerical methods....
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01 Jan 2006
TL;DR: In this article, the authors used the finite element method to investigate the vibration characteristics of thermally stressed/buckled laminated plates in the pre-and postbuckling states.
Abstract: Vibration and stability characteristics of composite laminates under thermo-mechanical loads have attracted the attention of many researchers in recent years as they are being increasingly used in thin walled structural components of aerospace, defense, reactor vessels and other high performance application areas. These studies were reviewed and well documented by Tauchert [1] and Noor and Burton [2]. It is observed from the existing literature that, the static buckling and postbuckling behavior of thermo-mechanically loaded rectangular and circular plates have been studied by many researchers. However, limited work has been done on the dynamic characteristics of thermally stressed/buckled laminated plates. Moreover, similar studies on thermo-mechanical vibration and stability characteristics of laminated composite plates other than rectangular/circular geometry have been sparsely treated in the published literature. Thermal load not only influences the stability characteristics of structures, but also changes its vibration frequencies. The notable recent contributions pertaining to small amplitude vibration behavior of thermally stressed/buckled rectangular composite plates may be found in Refs. [3–8]. Chang and Jen [3] studied influences of temperature change and large amplitude on the period of vibration of orthotropic rectangular plates. Noor and Burton [4] investigated the free vibration behavior of thermally stressed angle-ply composite plates using a three-dimensional thermo-elastic model. Librescu and Lin [5] employed single-term Navier-type double sine function to study the vibration behavior of thermo-mechanically loaded flat and curved composite panels taking into account interlaminar shear traction continuity requirement and considering a higher order shell theory. For accurate solution, the assumed mode shape function in the analytical approach should have more terms, thus leading to more numerical work. Numerical methods, like the finite element method is preferable as there is no need for an a priori assumption of the mode shapes as the solution itself predicts the mode shapes. Lee and Lee [6] used the finite element method to investigate the vibration characteristics of thermally stressed composite plates in the preand postbuckling states. Similar studies on the vibration frequencies of thermally buckled piezolaminated composite plates, and composite plates embedded with shape memory alloy fibers were reported by Oh et al. [7] and Park et al. [8]. Moreover, the authors [6–8] employed
23 citations
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87 citations
TL;DR: By discarding Lurie's (1952) assumption of mode identity, it was shown that linear theory correctly predicts the frequency of all modes of a thermally stressed cantilever plate as well as the frequency and modes of plates with other boundary conditions as discussed by the authors.
Abstract: By discarding Lurie's (1952) assumption of mode identity, it is shown that linear theory correctly predicts the frequency of all modes of a thermally stressed cantilever plate as well as the frequency and modes of plates with other boundary conditions The thermal stress distribution is obtained for whatever temperature distribution and boundary conditions that may be specified Experimental results are compared to calculated results for several different plates Boundary conditions for the plates range from a plate with edges completely clamped to a plate with edges completely free with various other combinations of mixed and uniform edge conditions Comparison of calculated data to experimental data shows that accurate, quantitative results can be obtained from linear theory for 'as cut' real plates for a significant range of heating when the assumption of mode identity is discarded
43 citations
TL;DR: In this paper, a Rayleigh-Ritz approach is used for the solution of elastic buckling and flexural vibration problems of thin rectangular plates which may be subject to any practical in-plane stress field.
38 citations
TL;DR: A theoretical and experimental study of the effect of weld runs on the flexural vibrational characteristics of the common structural element, the rectangular plate, is described in this article, where a finite difference technique is utilized for the determination of the in-plane residual stress pattern due to the weld(s) and the Rayleigh-Ritz method, with beam characteristic functions, is used for the out-of-plane vibration analysis.
20 citations