scholarly journals Vibration and Modal Analysis of Low Earth Orbit Satellite

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Asif Israr

This paper presents design, modeling, and analysis of satellite model used for remote sensing. A detailed study is carried out for the design and modeling of the satellite structure focusing on the factors such as the selection of material, optimization of shape and geometry, and accommodation of different subsystems and payload. The center of mass is required to be kept within the range of (1-2) cm from its geometric center. Once the model is finalized it is required to be analyzed by the use ofAnsys, a tool for finite element analysis (FEA) under given loading and boundary conditions. Static, modal, and harmonic analyses inAnsysare performed at the time of ground testing and launching phase. The finite element analysis results are also validated and compared with the theoretical predictions. These analyses are quite helpful and suggest that the satellite structure does not fail and retains its structural integrity during launch environment.

1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.


2021 ◽  
Vol 335 ◽  
pp. 03011
Author(s):  
Mohammed Shariff Mohamed Sulaiman ◽  
Seong Chun Koay ◽  
Ming Yeng Chan ◽  
Hui Leng Choo ◽  
Ming Meng Pang ◽  
...  

This research investigated the lattice structure fabricated using corn husk fibre reinforced recycled polystyrene composite using Finite Element Analysis (FEA). The material’s properties of this composite material were obtained from previous study. Then, the lattice structure of lattice structure was created using Creo® software and the FEA simulation was done by ANSYS software. In this study, the lattice structures were created using triangular prism and hexagonal prism. The analysis was divided into two conditions: 1) lattice structure with different prism shape and similar surface area, 2) lattice structure with varies of strut thickness and 3) lattice structure with different prism shape and similar lattice parameter. The results show the lattice structure with triangular prism have more structural integrity than hexagonal prism. Then, lattice structure with triangular prism can be built with lesser material but stronger and stiffer than lattice structure with hexagonal prism.


Author(s):  
Hui Tang ◽  
Yangmin Li ◽  
Jiming Huang

This article presents a novel design of a flexure-based, piezoelectric actuated, completely decoupled, high-bandwidth, highresolution, and large stroke parallel XY micromanipulator with two amplification levers. The monolithic mechanism is featured with dual working modes, which meets different kinds of requirements in terms of high resolution and large workspace in micro/nano fields. In order to reduce the displacement loss, the modeling and analysis of bending motion of the levers are conducted; thereafter, compliance and stiffness modeling by employing the matrix method are established. Furthermore, the dynamics modeling and analysis via Lagrange equations are performed to improve the dynamic properties of the mechanism. The simulation results of finite element analysis indicate that the cross-coupling between the two axes is kept to 1.2%; meanwhile, the natural frequency of the mechanism is about 700 Hz, and the amplifier ratio is approximately 2.32. Both theoretical analysis and finite element analysis results well validate the performance of the proposed mechanism.


2005 ◽  
Vol 127 (1) ◽  
pp. 34-37 ◽  
Author(s):  
Ravi Chandra Sikakollu ◽  
Lemmy Meekisho ◽  
Andres LaRosa

This paper deals with the design and analysis of a horizontal thermal actuator common in MEMS applications using Finite Element Analysis; with the objective of exploring means to improve its sensitivity. The influence of variables like voltage and the dimensions of the cold arm of the actuator unit were examined by comprehensive, coupled thermal-stress analyses. Simulation results from this study showed that the sensitivity of the actuator increases with the applied voltage as well as the width of the cold arm of the thermal actuator. An important observation made from this study is that the size and thermal boundary conditions at the fixed end of the actuator primarily control the stroke and the operating temperature of the actuator for a given potential difference between cold and hot arms. The coupled field analyses also provided a design tool for maximizing the service voltage and dimensional variables without compromising the thermal or structural integrity of the actuator.


2013 ◽  
Vol 712-715 ◽  
pp. 1111-1115
Author(s):  
Bei Li ◽  
Zhuan Wang ◽  
Yi Li Wang

A kind of calculating model was proposed according to the structure and load characteristics of push-back rack. On the basis of study on modeling and analysis technology using ANSYS, the finite element analysis of push-back rack was realized, which can provide reference to the design and calculation of push-back rack.


Author(s):  
Muhammad Abid ◽  
Abdul W. Awan

A number of analytical and experimental studies have been conducted to study ‘strength’ and ‘sealing capability’ of bolted flange joint only under internal pressure loading. Due to the ignorance of the external i.e. axial loading, the optimized performance of the bolted flange joint can not be achieved. A very limited work is found in literature under combined internal pressure and axial loading. In addition, the present design codes do not address the effects of axial loading on the structural integrity and sealing ability of the flange joints. From previous studies, non-gasketed joint is claimed to have better performance as compared to conventional gasketed joint. To investigate non-gasketed joint’s performance i.e. joint strength and sealing capability under combined internal pressure and any applied external loading, an extensive 3D nonlinear finite element analysis is carried out and overall joint performance and behavior is discussed.


2013 ◽  
Vol 288 ◽  
pp. 228-232
Author(s):  
Ye Fei ◽  
Yan Jun Liu ◽  
Yuan Yuan Li

In this paper, by defining and associating the boom structure parameter characteristic of truck crane, we build a parameterized automatic analysis system of truck crane boom, based on the VB platform with the ANSYS APDL language. In the system, the basic parameters of the crane structural finite element analysis can be obtained by human-computer exchange, achieving the finite element automatic modeling and analysis of boom structure under the driving of the parameters. Engineering examples show that the system is reliable and accurate results.


Author(s):  
Huifeng Jiang ◽  
Xuedong Chen ◽  
Zhichao Fan

Heretofore, several kinds of codes are applicable to the structural integrity assessment for pipe containing defects, i.e. API 579, R6 and BS 7910 etc. In this paper, different methods from API 579-1/ASME FFS-1: 2007 and R6-2000 were employed to assess the integrity of pipe containing a circumferential through-thickness crack. However, there was a significant difference between the calculated load ratios by these two codes, although the calculated fracture ratios were very close. To verify these results, elastic-plastic finite element analysis was carried out to calculate the limit load and the load ratio. Additionally, the experimental results and our previous engineering experience were also referred to. The final results imply that the larger load ratio obtained from R6-2000 rather than API 579 code is more reasonable for the pipe with good fracture toughness.


2021 ◽  
Author(s):  
Ibrahim M. Al Awadhi ◽  
Ashok M. Sharma ◽  
Sohail Akhter

Abstract Objective/Scope (25 - 75 word) Shell & Tube Heat exchangers are critical for incessant operation of processing plant. These exchangers may face integrity threats due to reduction in shell thicknesses at Nozzle to Shell Junction below design code requirements. This paper presents the Cost Effective fit for purpose approach utilizing advance Finite Element analysis to explore and recommend the solutions for existing numerous exchangers that are to be safely used even after reported low thickness on account of manufacturing imperfection. Methods, Procedures, Process (75 - 100 word) Reduction in Shell thickness below design value can affect its ability to sustain design pressure & vacuum including nozzle integrity for associated piping loads and service life reduction for exclusion of corrosion allowance. As short-term Mitigation methodology, weld overlay was adopted to restore the areas with lower thickness. For long term solution, fit for purpose review approach was adopted for continued usage of exchangers which involves nozzle load analysis using WRC & FEA based on PAUT thickness data and utilizing actual piping loads, derating of design pressure, comparison of thickness data to establish corrosion rate and service life of exchanger. Results, Observations & Conclusions (100 - 200 words) Thorough Integrity review based on design Code (ASME BPVC Section VIII) and WRC analysis have confirmed that majority of the exchangers have thickness higher than that required to sustain design pressure, vacuum conditions when considered with piping loads acting on nozzles. Thickness data comparison between three (03) year old manual UT and latest Phase array UT confirmed that majority of the exchangers are in clean non-corrosive service thus allowance for corrosion is not required. Where in the nature of exchanger service require corrosion allowance, it is considered in analysis and usage of stiffeners at nozzle to shell intersection and/or on full circumference of shell is recommended to prevent overstress due to piping loads / buckling distortion due to vacuum conditions respectively, based on detailed Finite element analysis (FEA). In order to establish more reliable long-term corrosion rate, next inspection after four (04) years is recommended and impact on integrity can be further evaluated based on the latest data. Change in exchanger nameplate is recommended to consider for design pressure as MAWP and accordingly adjust hydro test pressure followed by R-stamp requirements for rerating and repair. Shell side hydro test is restricted until recommendations are implemented Novel/Additive Information (25 - 75 words) Although conventional approach of replacing complete Shells to meet code requirement would have ensured process safety, performance and structural integrity. However, alternative fit for purpose approach utilizing advanced FEA has not only ensured all these but also led to potential cost saving of multimillion US$. Associated risks of thickness reduction due to corrosion may still be observed, however analysis confirmed structural integrity and safety of heat exchangers with low thicknesses. Accordingly, potential risk is mitigated.


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