Deformation and Stability of Gold/Polysilicon Layered MEMS Plate Structures Subjected to Thermal Loading

2008 ◽  
pp. 306-306-12 ◽  
Author(s):  
ML Dunn ◽  
Y Zhang ◽  
VM Bright
Keyword(s):  
Thermal Loading ◽  
Plate Structures

Dynamic Response of Three-Layered Annular Plates in Time-Dependent Temperature Field

2020 ◽  
Vol 20 (12) ◽  
pp. 2050139
Author(s):  
Dorota Pawlus
Keyword(s):  
Temperature Field ◽  
Dynamic Response ◽  
Thermal Loading ◽  
Dynamic Responses ◽  
Time Dependent ◽  
The Finite Element Method ◽  
Plate Structures ◽  
Buckling Modes ◽  
Annular Plates ◽  
Axisymmetric Temperature

The paper presents a solution to the dynamic response of three-layered, annular plates that are thermo-mechanically loaded. Time-dependent forces are considered to act on the facings of the plate. The thermal loading is defined by a flat, axisymmetric temperature field whose profile is expressed by the stationary or increase in time temperature differences between the plate edges. The cases of the plates loaded only thermally or mechanically have been examined. The problem has been solved analytically and numerically using the approximation methods: orthogonalization and finite difference. The selected reactions of an exemplar plate have been compared with the results obtained for the plate analyzed by the finite element method (FEM). The critical temperature differences and critical loads and corresponding dynamic buckling modes have been analyzed in detail. The numerous results presented for the dynamic responses have an important and practical meaning in the design process of plate structures subjected to complex thermo-mechanical loads.

A Method for Reliability Assessment of Spatial Plate Structures Through Automatic Generation of Ultimate Collapse Modes

1991 ◽  
Vol 1991 (170) ◽  
pp. 483-491 ◽  
Author(s):  
Hiroo Okada ◽  
Yoshisada Murotsu ◽  
Keiji Ueyama ◽  
Minoru Harada ◽  
Kazuya Kondo
Keyword(s):  
Reliability Assessment ◽  
Automatic Generation ◽  
Plate Structures

Pull-in Dynamics of Two MEMS Parallel-plate Structures for Acceleration Measurement

2021 ◽  
pp. 1-1
Author(s):  
Zhipeng Ma ◽  
Xiaojun Jin ◽  
Yixuan Guo ◽  
Tengfei Zhang ◽  
Yiming Jin ◽  
...  
Keyword(s):  
Parallel Plate ◽  
Acceleration Measurement ◽  
Plate Structures

Random impact FEM simulation of irregularly-shaped media for parametric study of vibratory surface enhancement

2021 ◽  
pp. 095440542199012
Author(s):  
Jing Zhang ◽  
Joselito Yam Alcaraz ◽  
Swee-Hock Yeo ◽  
Arun Prasanth Nagalingam ◽  
Abhay Gopinath
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Parametric Study ◽  
Thermal Loading ◽  
Low Cycle Fatigue ◽  
Fem Simulation ◽  
Surface Finishing ◽  
Aerospace Materials ◽  
Surface Enhancement ◽  
Steel Balls

Aerospace materials experience high levels of mechanical and thermal loading, high/low cycle fatigue, and damage from foreign objects during service, which can lead to premature retirement. Mechanical surface treatments of metallic components, for example, fan blades and blisks, are proven to improve fatigue life, improve wear resistance and avoid stress corrosion by introducing work hardening, compressive residual stresses of sub-surface, and surface finishing. Vibropeening can enhance aerospace materials’ fatigue life involving the kinetic agitation of hardened steel media in a vibratory finishing machine that induces compressive stresses into the component sub-layers while keeping a finished surface. Spherical steel balls are the most widely used shape among steel-based media and have been explored for decades. However, they are not always versatile, which cannot access deep grooves, sharp corners, and intricate profiles. Steel ballcones or satellites, when mixed with round steel balls and other steel media (diagonals, pins, eclipses, cones), works very well in such areas that ball-shaped media are unable to reach. However, a methodology of study the effect of irregularly-shaped media in surface enhancement processes has not been established. This paper proposes a finite element-based model to present a methodology for the parametric study of vibratory surface enhancement with irregularly-shaped media and investigates residual stress profiles within a treated area of an Inconel component. The methodology is discussed in detail, which involves a stochastic simulation of orientation, impact force, and impact location. The contrasting effects of a high aspect ratio, or an edge contact, as opposed to rounded and oblique contacts are demonstrated, with further analysis on the superposition of these effects. Finally, the simulation results are compared with actual residual stress measurements and was found to have a max percent difference of 34% up to 20 [Formula: see text]m below the media surface.

scholarly journals Mechanical Performance of a Ballastless Track System for the Railway Bridges of High-Speed Lines: Experimental and Numerical Study under Thermal Loading

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2876
Author(s):  
Yingying Zhang ◽  
Lingyu Zhou ◽  
Akim D. Mahunon ◽  
Guangchao Zhang ◽  
Xiusheng Peng ◽  
...  
Keyword(s):  
High Speed ◽  
Thermal Loading ◽  
Mechanical Performance ◽  
Track Structure ◽  
Box Girder ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Track System ◽  
Girder Bridge ◽  
Track Slab

The mechanical performance of China Railway Track System type II (CRTS II) ballastless track suitable for High-Speed Railway (HSR) bridges is investigated in this project by testing a one-quarter-scaled three-span specimen under thermal loading. Stress analysis was performed both experimentally and numerically, via finite-element modeling in the latter case. The results showed that strains in the track slab, in the cement-emulsified asphalt (CA) mortar and in the track bed, increased nonlinearly with the temperature increase. In the longitudinal direction, the zero-displacement section between the track slab and the track bed was close to the 1/8L section of the beam, while the zero-displacement section between the track slab and the box girder bridge was close to the 3/8L section. The maximum values of the relative vertical displacement between the track bed and the bridge structure occurred in the section at three-quarters of the span. Numerical analysis showed that the lower the temperature, the larger the tensile stresses occurring in the different layers of the track structure, whereas the higher the temperature, the higher the relative displacement between the track system and the box girder bridge. Consequently, quantifying the stresses in the various components of the track structure resulting from sudden temperature drops and evaluating the relative displacements between the rails and the track bed resulting from high-temperature are helpful in the design of ballastless track structures for high-speed railway lines.

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