The Dynamic Finite Element Modeling of Aircraft Landing System

Author(s):  
Craig F. Chang

Abstract The objective of this paper is to address finite element modeling for dynamics and its applications to aircraft landing and braking systems. The components of the system in the example model include the entire landing gear, wheels, brakes, and tires. The use of finite element modeling techniques in dynamics as a design tool for landing and braking systems is discussed. Vibration mode shapes from the finite element analysis, including both whirl and squeal, are shown. Correlation between the finite element models and the experimental modal analyses of various system components are presented. Correlation between the performance of the complete landing and braking system model and the actual system during aircraft operation is also presented.

2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Zhao Xu ◽  
Zezhi Rao ◽  
Vincent J. L. Gan ◽  
Youliang Ding ◽  
Chunfeng Wan ◽  
...  

Mesh generation plays an important role in determining the result quality of finite element modeling and structural analysis. Building information modeling provides the geometry and semantic information of a building, which can be utilized to support an efficient mesh generation. In this paper, a method based on BRep entity transformation is proposed to realize the finite element analysis using the geometric model in the IFC standard. The h-p version of the finite element analysis method can effectively deal with the refined expression of the model of bending complex components. By meshing the connection model, it is suggested to adopt the method of scanning to generate hexahedron, which improves the geometric adaptability of the mesh model and the quality and efficiency of mesh generation. Based on the extension and expression of IFC information, the effective finite element structure information is extracted and extended into the IFC standard mode. The information is analyzed, and finally the visualization of finite element analysis in the building model can be realized.


2014 ◽  
Vol 697 ◽  
pp. 226-229
Author(s):  
Cai Ling Wang ◽  
Hong Wei Wang

According to flexible connectivity of space stabilization system,This paper proposes the finite element analysis method using multiple equivalent spring connecting unit to replace the original flexible connections. And the elastic coefficient’s correspondence between the equivalent spring and the original spring were deduced. Using the equivalent spring method, the tip/tilt mirror system for finite element modeling is completed, After completion of the modal analysis, first-order resonant frequency is calculated. At last, the tip/tilt mirror system is tested in non-contact laser resonance detection system, And test results and modal analysis results were compared, and results show that the finite element modeling method of using equivalent spring connecting is effective. Provide constructive reference for subsequent tip/tilt mirror design, has a very important reference for similar projects.


Author(s):  
Anagha G. Jog ◽  
Ian R. Grosse ◽  
Daniel D. Corkill

Abstract Currently, the pre-processing stage of finite element analysis is a major stumbling block towards automation of the entire finite element modeling and analysis (FEMA) process. The lack of complete automation of FEMA greatly limits its impact as a design tool. This paper presents a blackboard-based, object-oriented modeling system for intelligent a-priori automatic three dimensional mesh generation. The modeling system enables the user to define the physical system at a natural domain-specific high level of abstraction and automatically derives lower-level finite element model representations. Knowledge sources interact with the blackboard to make modeling idealizations and select optimal meshing strategies. An example application in the domain of finite element modeling of multi-chip module microelectronic devices is presented.


Author(s):  
Paul M. Kurowski

The Finite Element Analysis (FEA) is becoming increasingly popular among design engineers using it as one of many product design tools. Safe and cost efficient use of FEA as a product design tool requires training, different from that presently found in undergraduate curriculum of mechanical engineering students. The specific requirements of design engineers for training in the field of FEA have been addressed by the author in a number of professional development courses in FEA, catering specifically to the needs of design engineers. This paper discuses tools and methods used in the development and delivery of these courses and their applicability to the undergraduate courses taught in Canadian Engineering schools.


1999 ◽  
Vol 121 (4) ◽  
pp. 984-988 ◽  
Author(s):  
Alex Y. Tsay ◽  
Jin-Hui Ouyang ◽  
C.-P. Roger Ku ◽  
I. Y. Shen ◽  
David Kuo

This paper studies natural frequencies and mode shapes of a glide head with a piezoelectric transducer (PZT) through calibrated experiments and a finite element analysis. In the experiments, the PZT transducer served as an actuator exciting the glide head from 100 kHz to 1.3 MHz, and a laser Doppler vibrometer (LDV) measured displacement of the glide head at the inner or outer rail. The natural frequencies were measured through PZT impedance and frequency response functions from PZT to LDV. In the finite element analysis, the glide head was meshed by brick elements. The finite element results show that there are two types of vibration modes: slider modes and PZT modes. Only the slider modes are important to glide head applications. Moreover, natural frequencies predicted from the finite element analysis agree well with the experimental results within 5% of error. Finally, the finite element analysis identifies four critical slider dimensions whose tolerance will significantly vary the natural frequencies: PZT bonding length, wing thickness, slider thickness, and air bearing recess depth.


Author(s):  
Santosh Shanbhag ◽  
Ian R. Grosse ◽  
Jack C. Wileden ◽  
Alan Kaplan

Abstract With the integration of CAD and FEA software packages, design engineers who are not skilled in finite element analysis are performing finite element modeling and analysis. Furthermore, in the analysis of a system, engineers often make numerous modeling simplifications and analysis assumptions depending on the trade-off between cost, accuracy, precision or other engineering analysis objectives. Thus, reusability or interoperability of engineering analysis models is difficult and often impractical due to the wealth of knowledge involved in the creation of such models and the lack of formal methods to codify and explicitly represent this critical modeling knowledge. Most institutions and organizations have started documenting these simplifications and assumptions, making them understandable for the other engineers within the organization. However, this does not allow a seamless exchange of data or interoperability with other analysis models of similar or dissimilar nature. This plays a very important role in today’s market, which is moving away from the traditional make-to-stock production model to a build-to-demand model. We address these issues in this paper by adopting and extending the computer science concept of meta-object, and applying it in novel ways to the domain of FEA and the representation of finite element modeling knowledge. We present a taxonomy for engineering models that aids in the definition of the various object analysis classes. A simple beam analysis example, followed by a more realistic injection-molded part example. The latter example involves injection-mold filling simulation, thermal cooling, and part ejection analyses which are subclasses for a generic manufacturing analysis meta-object class. Prototype implementations of automated support for this meta-object approach to finite element modeling is in progress.


2019 ◽  
Vol 799 ◽  
pp. 211-216
Author(s):  
Alina Sivitski ◽  
Priit Põdra

Contact modeling could be widely used for different machine elements normal contact pressure calculations and wear simulations. However, classical contact models as for example Hertz contact models have many assumptions (contact bodies are elastic, the contact between bodies is ellipse-shaped, contact is frictionless and non-conforming). In conditions, when analytical calculations cannot be performed and experimental research is economically inexpedient, numerical methods have been applied for solving such engineering tasks. Contact stiffness parameters appear to be one of the most influential factors during finite element modeling of contact. Contact stiffness factors are usually selected according to finite element analysis software recommendations. More precise analysis of contact stiffness parameters is often required for finite element modeling of contact.


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