Analysis of Hybrid Programming Simulation Based on the Variable Stiffness Ring With Expanding Loop SMA Actuator

2017 ◽  
Author(s):  
Lei Wang ◽  
Zong-quan Deng ◽  
Hao-di Wang ◽  
Hong-hao Yue
Keyword(s):  
Thermal Stress ◽  
Elastic Modulus ◽  
Active Control ◽  
Driving Force ◽  
Structure Design ◽  
Smart Structure ◽  
Space Craft ◽  
Stiffness Variation ◽  
Sma Actuator ◽  
Driving Source

In the development of space craft design index, the requirements of hypersonic space craft control accuracy has been increasingly rigorous. Thin-walled structure is often employed in hypersonic craft to reduce the weight of the load and to save the room. During the flight of the craft, temperature field is produced along the surface and the dynamic properties of the craft structure are obviously changed. The decreasing elastic modulus of the structure material and the appearance of thermal stress lead to the decrease of integral rigidity and stability of the structure, then the thermal flutter appears and control difficulties increase. Shape Memory Alloy (SMA) has the advantages of the considerable driving force in the compact volume and the simple driving method. By the combination of actuator structure design and stiffness control, the smart structure is able to make active control to the thermal stiffness variation. In this paper, the apex high-temperature area is equivalent to a ring structure. Finite difference method is employed firstly to transform the governing partial differential equation into discrete finite difference equations. Then the elastic modulus change, thermal stress and tension along the circumference are considered comprehensively to propose the calculation formulas of equivalent young’s modulus. The discrete dynamic matrix model is obtained containing the control terms of SMA. To solve the big-matrix calculation and multiple iterated large data problem, hybrid program is developed with C++ and MATLAB. Finite element software is employed to make optimization analysis to design an expanding loop actuator containing SMA as driving source, variable thickness loops of spring steel as expanding units, and universal-ball pre-loading units. On the basis of that, the thermal stiffness variation active control system with smart structure is developed based on expanding loop SMA actuator. After the analysis of examples, the variation law of the needed SMA driving force is obtained. The distribution position and quantity of the driving source is optimized. This research provides reference for the Theoretical Analysis and Simulation of structure stiffness active control and adaptive control of the aircraft employing smart material. The research results have guiding significance for the smart structure design of hypersonic aircraft in the future.

FEM Analysis of Contact for Converter Spherical Hinge

2013 ◽  
Vol 365-366 ◽  
pp. 331-334
Author(s):  
Xue Ping Ren ◽  
Jian Da Gao
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Optimum Design ◽  
Theoretical Basis ◽  
Fem Analysis ◽  
Structure Design ◽  
Coupling Field ◽  
Main Components ◽  
Spherical Hinge

The role of converter spherical hinge is one of the main components, combined with practical work and With help of FEM, Thermal Stress coupling field of spherical washer can been obtained through numerical simulation. The result supplies substantial theoretical basis for further structure design and optimum design of mechanism.

Simulation and Analysis of the Thermal Stress in Concrete under Temperature Fluctuation Condition

2010 ◽  
Vol 168-170 ◽  
pp. 1957-1960
Author(s):  
Ya Ding Zhao ◽  
Xue Ying Li ◽  
Hong Yang Liu
Keyword(s):  
Temperature Field ◽  
Thermal Stress ◽  
Elastic Modulus ◽  
Stress Distribution ◽  
Thermal Gradient ◽  
Structural Dimension ◽  
Temperature Field Distribution ◽  
Air Content ◽  
Thermal Stress Distribution ◽  
The Relationship

The temperature field distribution and thermal stress distribution in concrete has been studied by finite elements method to establish the relationship between the thermal stress and the temperature in this paper. The results show that the maximum thermal gradient and the maximum thermal stress in the concrete appears on the direction of greater structural dimension, and the thermal stress value is positively correlated with thermal gradient or saying temperature difference and elastic modulus, and is negatively correlated with the water content and air content.

Effect of Temperature on the Material Properties and the Results of Thermal Stress Analysis

2017 ◽  
Vol 729 ◽  
pp. 8-12
Author(s):  
Tae Kyung Kim ◽  
Dong Kwon Oh ◽  
Kwang Ju Lee
Keyword(s):  
Thermal Stress ◽  
Elastic Modulus ◽  
Stress Analysis ◽  
Material Properties ◽  
Room Temperature ◽  
Test System ◽  
Effect Of Temperature ◽  
Air Conditioning System ◽  
Thermal Stress Analysis ◽  
Different Levels

Use of correct values of material properties is important in structural analysis. When incorrect values are used in the analysis, engineers may end up with misleading conclusions. The magnitudes of elastic modulus and strength are usually measured from experiments at room temperature. When these values are used in the thermal stress analysis of structures, the results may not be reliable because the magnitudes of elastic modulus and strength depend on temperature. The temperature distribution of HVAC (Heating, Ventilation and Air Conditioning) system was analyzed. The material properties were measured using MTS810 material test system and MTS 651 environmental chamber at different levels of temperature. They were used in the thermal stress analysis of HVAC system. It was found that the results of thermal stress analysis were significantly different from the results using material properties which were measured from experiments at room temperature.

Optimum Structure Design of a Multilayer Piezo-Composite Disk for Control of Thermal Stress

2012 ◽  
Vol 35 (9) ◽  
pp. 805-819 ◽  
Author(s):  
Ahmed Elsawaf ◽  
Fumihiro Ashida ◽  
Sei-ichiro Sakata
Keyword(s):  
Thermal Stress ◽  
Structure Design ◽  
Optimum Structure ◽  
Composite Disk

FEM Analysis on Thermal Stress of Desulphurization Injection Lance

2007 ◽  
Vol 336-338 ◽  
pp. 1531-1533
Author(s):  
Jian Qiang Qi ◽  
Yong Huang ◽  
Shi Xi Ouyang ◽  
Nan Li ◽  
Jiang Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Finite Element Method ◽  
Finite Element ◽  
Thermal Stress ◽  
Elastic Modulus ◽  
Fem Analysis ◽  
Finite Element Method Model ◽  
Method Model ◽  
Element Method

By means of a finite element method model, the effects of property parameters of refractory on thermal stress of injection lance have been studied. The results show that the maximum thermal stress increases with the improvement of thermal conductivity and elastic modulus of refractory, while it decreases at first and then increases with the improvement of the coefficient of expansion of refractory.

Experimental Study on the Influence of Temperature on Shale Mechanical Properties under Conventional Triaxial Compression

2011 ◽  
Vol 250-253 ◽  
pp. 1452-1455 ◽  
Author(s):  
Lu Bo Meng ◽  
Tian Bin Li ◽  
Liang Wen Jiang ◽  
Hong Min Ma
Keyword(s):  
Mechanical Properties ◽  
Thermal Stress ◽  
Elastic Modulus ◽  
High Temperature ◽  
Poisson’S Ratio ◽  
Triaxial Compression ◽  
Poisson's Ratio ◽  
Influence Of Temperature ◽  
Conventional Triaxial Compression ◽  
Influence Of Temperature On

High temperature conventional triaxial compression test of shale are carried out by the MTS815 servo-controlled testing machine, based on the experimental results, the relationships between temperature and shale peak strength, elastic modulus, Poisson's ratio, cohesion, internal friction angle are investigated. Although the experimental results are discrete comparatively, the general law is obvious. When the confining pressure imposed on shale is constant and the temperature changes form 25°C to 120°C, with the increasing of the temperature, the triaxial compression strength, shear strength gradually increase, while average elastic modulus, Poisson's ratio has a slightly decrease. The thermal stress generated by the high temperature plays a role to accommodate the deformation and the function of preventing crack propagation, thus the bearing capacity of shale samples are strengthened. But the influence of temperature on shale mechanical properties mutates when the temperature is at 80°C. Shale peak strength dramatically decreased, average elastic modulus decreased slightly, and Poisson's ratio also increased slightly, which indicated that at 80°C, different thermal expansivity of mineral particles of shale may cause cross-grain boundary thermal expansion incongruous, creating additional thermal stress, thus the sample’s bearing capacity decreased.

Experimental Study on the Axial Compressive Strength and Elastic Modulus of GHPFRCC

2013 ◽  
Vol 357-360 ◽  
pp. 1138-1141 ◽  
Author(s):  
Xiu Ling Li ◽  
Wang Juan
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
High Performance ◽  
Construction Material ◽  
Structure Design ◽  
Sustainable Construction ◽  
High Performance Fiber ◽  
Maintenance Decisions ◽  
Axial Compressive Strength ◽  
Pva Fiber

The sustainability of the construction material is increasingly coming to the forefront of the structure design and maintenance decisions. To address this, development of a new class of more sustainable construction material is needed, especially in China. This paper reports on the development of the green high-performance fiber-reinforced cementitious composites (GHPFRCC) with high volumes of fly ash and PVA fiber, and emphasizes the axial compressive strength and elastic modulus of GHPFRCC. Experimental results show that the prism axial compressive strength of GHPFRCC ranges from 15MPa to 40MPa. The elastic modulus of GHPFRCC is around 16-35GPa, typically lower than concrete.

Research on the Impact of Vent Pressure on the Yarn Splicing Based on ANSYS

2013 ◽  
Vol 584 ◽  
pp. 50-53
Author(s):  
De Gong Chang ◽  
Deng Chen Li ◽  
Song Mei Li ◽  
Guang Zhen Zhou ◽  
Hai Xia Zhao
Keyword(s):  
Driving Force ◽  
High Speed ◽  
Structure Design ◽  
Hole Diameter ◽  
Ansys Software ◽  
Modeling Analysis ◽  
Solid Foundation ◽  
The Impact ◽  
Chamber Diameter

Pneumatic splice makes use of high-speed compressed air as the driving force to complete the yarn splicing, noticing that the change of the vent pressure has a significant effect on yarn splicing. This paper studies the impact of vent pressure on the quality of yarn splicing when twisting and untwisting. Modeling, analysis and simulation of the air splice is done with the integration of Pro/E and ANSYS software, to study the flow filed and obtain the influence on the speed and pressure of the inside the splicing chamber when changing the speed and pressure while keeping the diameter of splicing chamber diameter, the vent hole diameter and the relative angle are unchanged. The results of the analysis of the air splice will lay a solid foundation for the further optimized structure design.

Smart Structures—a Concept or a Reality?

1992 ◽  
Vol 206 (1) ◽  
pp. 1-8 ◽  
Author(s):  
B Culshaw
Keyword(s):  
Driving Force ◽  
Smart Structures ◽  
Aerospace Industry ◽  
Future Generation ◽  
Smart Structure ◽  
First Century ◽  
Future Trends ◽  
European Context ◽  
Reaction Capability ◽  
Basic Ideas

A smart structure has intelligence and reaction capability embedded within it. Consequently, via a sensor and actuator network, it can respond to external environmental or operational requirements. The most obvious driving force stimulating the need for smart structures lies within the aerospace industry but civil engineering interests have already exploited the ideas in, for example, compensating for earth tremors. There may even be a potential to be exploited by a future generation of toy manufacturers. This paper will illustrate the principles underlying the concepts referring to current, evolving and futuristic technologies. It will also assess the present exploitation of the basic ideas and will indicate future trends, making the comparison between European, Japanese and American philosophies towards this rapidly evolving subject. The successful exploitation of smart structure concepts will prove to be vital in twenty-first-century engineering. Potential paths whereby this exploitation may be realized in a European context will be discussed.

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