Mechanical and thermal stability of eccentrically stiffened functionally graded conical shell panels resting on elastic foundations and in thermal environment

2015 ◽  
Vol 132 ◽  
pp. 597-609 ◽  
Author(s):  
Nguyen Dinh Duc ◽  
Pham Hong Cong ◽  
Vu Minh Anh ◽  
Vu Dinh Quang ◽  
Phuong Tran ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Conical Shell ◽  
Thermal Environment ◽  
Functionally Graded ◽  
Elastic Foundations ◽  
Thermal Stability Of

Free vibration response of carbon nanotube reinforced pretwisted conical shell under thermal environment

2019 ◽  
Vol 234 (3) ◽  
pp. 770-783 ◽  
Author(s):  
Pabitra Maji ◽  
Mrutyunjay Rout ◽  
Amit Karmakar
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element ◽  
Carbon Nanotube ◽  
Free Vibration ◽  
Conical Shell ◽  
Dynamic Equilibrium ◽  
Thermal Environment ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Mode Shapes

Finite element procedure is employed to analyze the free vibration characteristics of rotating functionally graded carbon nanotubes reinforced composite conical shell with pretwist under the thermal environment. In this paper, four types of carbon nanotube grading are considered, wherein the distribution of carbon nanotubes are made through the thickness direction of the conical shell. An eight-noded isoparametric shell element is used in the present formulation to model the panel based on the first-order shear deformation theory. For moderate rotational speeds, the generalized dynamic equilibrium equation is derived from Lagrange’s equation of motion, neglecting the Coriolis effect. The finite element code is developed to investigate the effect of twist angle, temperature, aspect ratio, and rotational speed on natural frequencies. The mode shapes of a carbon nanotube reinforced functionally graded conical shell at different twist angles and rotational speeds are also presented.

scholarly journals Thermal Stability Analysis of the Mg/TeO2 Ignition Composition after 180 °C Exposure

2020 ◽  
Vol 10 (22) ◽  
pp. 8122
Author(s):  
Xiang He ◽  
Yaokun Ye ◽  
Nan Yan ◽  
Feng Ding ◽  
Chaozhen Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Environment ◽  
Exothermic Reaction ◽  
Pressure Rise ◽  
Optical Microscope ◽  
Main Reaction ◽  
Scanning Calorimetry ◽  
Change Analysis ◽  
Good Thermal Stability ◽  
Thermal Stability Of

In order to satisfy the performance requirements of the pyrotechnic ignition composition of a space mission under an extreme thermal environment, it is necessary to analyze and verify the thermal stability of magnesium/tellurium dioxide (Mg/TeO2) ignition composition at a temperature of 180 °C. The thermal stability of the ignition composition of Mg/TeO2 and its components after exposure to 180 °C for 2–10 days was studied by means of apparent morphology analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), content change analysis, and the P-t curve test. The results showed that after exposure to 180 °C for 2–10 days, no obvious changes, such as ruptures, expansion, or shrinkage, were found by optical microscope, and no changes in morphology and surface details were found by scanning electron microscope (SEM). XRD showed that no other new substance was found in the mixture except magnesium hydroxide (Mg (OH)2). DSC showed that the main reaction peak temperature of the ignition composition of Mg/TeO2 was after 500 °C and that no endothermic/exothermic reaction occurred before 380 °C. The exothermic pre-reaction took place at 381 °C to 470 °C, the weight loss ratio was within 0.71%, the content of the magnesium component varied from 0.49% to 0.90%, the peak pressure attenuation of the ignition composition of 360-mesh Mg/TeO2 was 8.07%, and the pressure rise time was basically unchanged. The results showed that the ignition composition of Mg/TeO2 had good thermal stability after exposure to 180 °C temperatures.

Nonlinear thermo-mechanical dynamic analysis and vibration of higher order shear deformable piezoelectric functionally graded material sandwich plates resting on elastic foundations

2016 ◽  
Vol 20 (2) ◽  
pp. 191-218 ◽  
Author(s):  
Nguyen Dinh Duc ◽  
Pham Hong Cong
Keyword(s):  
Dynamic Analysis ◽  
Material Properties ◽  
Nonlinear Dynamic ◽  
Thermal Environment ◽  
Nonlinear Dynamic Analysis ◽  
Higher Order ◽  
Functionally Graded ◽  
Geometrical Parameters ◽  
Sandwich Plates ◽  
Elastic Foundations

Used the Reddy's higher-order shear deformation plate theory, the nonlinear dynamic analysis and vibration of imperfect functionally graded sandwich plates in thermal environment with piezoelectric actuators (PFGM) on elastic foundations subjected to a combination of electrical, damping loadings and temperature are investigated in this article. One of the salient features of this work is the consideration of temperature on the piezoelectric layer, and the material properties of the PFGM sandwich plates are assumed to be temperature-dependent. The governing equations are established based on the stress function, the Galerkin method, and the Runge–Kutta method. In the numerical results, the effects of geometrical parameters; material properties; imperfections; elastic foundations; electrical, thermal, and damping loads on the vibration and nonlinear dynamic response of the PFGM sandwich plates are discussed. The obtained natural frequencies are verified with the known results in the literature.

On thermal stability of plates with functionally graded coefficient of thermal expansion

2016 ◽  
Vol 60 (2) ◽  
pp. 313-335 ◽  
Author(s):  
Abdelmoumen Anis Bousahla ◽  
Samir Benyoucef ◽  
Abdelouahed Tounsi ◽  
S.R. Mahmoud
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Functionally Graded ◽  
Thermal Stability Of
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