Physical and Geometrical Non-Linearities in Contact Problems of Elastic Turbine Blade Attachments

1995 ◽  
Vol 209 (4) ◽  
pp. 273-286 ◽  
Author(s):  
G Zboinski
Keyword(s):  
Finite Element ◽  
Turbine Blade ◽  
Linear Elasticity ◽  
Theoretical Basis ◽  
Contact Problems ◽  
Unilateral Constraints ◽  
Effective Stresses ◽  
Blade Root ◽  
Finite Element Calculations ◽  
Contact Surfaces

The paper presents briefly the theoretical basis of linear and non-linear contact problems of linear elasticity as applied to the kinetostatic analysis of turbomachinery blade attachments. The physical and geometrical non-linearities of the problem are due to friction and unilateral constraints respectively. For three classes of contact problems finite element calculations of a real fir-tree turbine blade attachment with and without clearances within the contact surfaces are performed. The results for effective stresses of the root and disc hooks are thoroughly analysed and compared. Furthermore, the results for contact node status and nodal slips between the blade root and the disc sector are presented. The significance of the physical and geometrical non-linearities to the stress, displacement and contact states of the attachment is then discussed.

A Reduced Full-System Finite Element Approach to the Solution of EHL Problems: Line Contacts

2010 ◽  
Author(s):  
W. Habchi ◽  
J. Issa
Keyword(s):  
Finite Element ◽  
Linear Elasticity ◽  
Degrees Of Freedom ◽  
Contact Problems ◽  
Full System ◽  
Acceptable Solution ◽  
Line Contacts ◽  
Order Of Magnitude ◽  
Element Approach ◽  
Basis Method

This paper presents a reduced full-system finite element solution of isothermal elastohydrodynamic (EHD) line contact problems. The proposed model is based on a full-system finite element resolution of the EHL equations: Reynolds, linear elasticity and load balance. A reduced model is proposed for the linear elasticity problem. For this, three different techniques are tested: the classical “Modal reduction” and “Ritz-vector” methods and a novel “EHL-basis” method. The reduction order in the first two appears to be insufficient and a large number of degrees of freedom is required in order to attain an acceptable solution. On the other hand, the “EHL-basis” method shows up to be much more efficient, requiring only a few degrees of freedom to compose the elastic deformation of the solid components. In addition, a comparison with the full model shows an order of magnitude cpu time gain with errors of the order of only 1‰ for the central and minimum film thicknesses.

Study of the Process of Turbine Blade and Fixture Design Based on UG and ANSYS

2011 ◽  
Vol 421 ◽  
pp. 369-372
Author(s):  
Jie Shao Xin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Analysis ◽  
Turbine Blade ◽  
Theoretical Basis ◽  
Three Dimensional ◽  
Processing Technology ◽  
Fixture Design ◽  
Ansys Software ◽  
Element Analysis

This paper made an analysis on the process of turbine blade, and completed the three-dimensional design of milling and cutting fixture used in the process on the UG software. After the stress analysis of the workpiece is completed, the author made a finite element analysis on both the blades and the main parts of the fixture with the help of ANSYS software, the results of the research provide theoretical basis for the development of reasonable processing technology and reliable workpiece assembly.

scholarly journals CLT beam analysis using classical elastic theory of layered beams

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
Markku Heinisuo ◽  
Sami Pajunen
Keyword(s):  
Finite Element ◽  
Theoretical Basis ◽  
Suitable Method ◽  
Elastic Theory ◽  
Test Results ◽  
Established Method ◽  
Cross Laminated Timber ◽  
Layered Beams ◽  
Beam Analysis ◽  
Finite Element Calculations

The classical elastic theory of layered beams is used for the analysis of cross laminated timber (CLT) beams. A brief introduction of the theory is given and followed by examples. The theory of layered beams offers a widely studied, well established method for the analysis the CLT beams including displacements and stresses of each layer of the beam. It is shown that the theoretical basis of the widely used Shear Analogy is the same as the theoretical basis of the theory of layered beams. The results are compared to test results and to results of the finite element calculations. It is seen that the deflections and strains are in 10 % fractals in mean in the considered cases. The theory of layered beams seems to be suitable method in the analysis of the CLT beams at the elastic phase.

Automation and Assessment of Augmented Lagrangian Algorithms for Frictional Contact Problems

1994 ◽  
Vol 61 (4) ◽  
pp. 956-963 ◽  
Author(s):  
T. A. Laursen ◽  
V. G. Oancea
Keyword(s):  
Finite Element ◽  
Augmented Lagrangian ◽  
Frictional Contact ◽  
Contact Problems ◽  
Effective Technique ◽  
Finite Element Calculations ◽  
Augmented Lagrangian Approach ◽  
Constraint Enforcement ◽  
Augmented Lagrangian Algorithms ◽  
User Intervention

In recent work, the augmented Lagrangian approach to large deformation frictional contact problems has been advocated for finite element calculations. The resulting algorithms have been shown to facilitate accurate constraint enforcement in a robust manner, while providing an effective technique for removal of the nonsymmetry associated with most frictional constitutive laws. In this work, we examine automation schemes for the algorithm, such that multipliers can be determined to a specified degree of accuracy without user intervention. The performance of the resulting automatic augmentation algorithm is then examined, providing important information about practical attributes of the procedure.

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