Numerical and experimental analysis of indentation

Koray, Erge
Indentation tests are widely used with simultaneous measurements of indentation depth and force especially for determining material properties. In this study; numerical and experimental investigation of the force-indentation measurements is presented. For indentation tests on anisotropic metals, a novel indenter which is not self similar is used with three transducers to measure the displacements. It is seen that in order to have high repeatability and accuracy at the tests, workpiece and indenter parameters have crucial importance. These parameters in the indentations are analyzed by finite element methods. Ideal dimensions of the workpiece are determined. It is shown that plane strain conditions can only be achieved by embedded indentations. Effect of surface quality and clamping on repeatability are investigated. It is shown that surface treatments have significant effects on the results. Also it is seen that clamping increases the repeatability drastically. Moreover, indentation tests are conducted to verify the results of numerical simulations. Effect of anisotropy on the force-displacement curves is clearly observed.


Numerical, analytical and experimental analysis of indentation
Topcu, Nagihan; Tekkaya, A. Erman; Department of Mechanical Engineering (2005)
Indentation is a practical and easy method, therefore, is a preferred method of material characterization. Main aim of this thesis study is to determine anisotropic properties of metals by indentation tests. The basic property of the indenter used in the finite element analyses and experiments is that it is specific to this process. Thesis includes studies on optimization of the indenter geometry, analyses of effects of friction coefficient, multiple indentations, tilting of the indenter and clamping of the...
Design of a touch trigger probe for a coordinate measuring machine
Karuç, Emre; Dölen, Melik; Department of Mechanical Engineering (2007)
Coordinate Measuring Machines (CMMs) have been widely used in industry in order to determine the form / dimensional tolerances of workpieces with very complicated geometrical shapes. Therefore, CMM is an important tool during the manufacturing and quality control phases. Workpiece to be measured on a CMM is probed via touch trigger probe through its stylus tip. In other words, by virtue of the touch trigger probes CMM can acquire the dimensional data of the workpiece that is to be measured. Therefore the pr...
Uncertainty analysis of coordinate measuring machine (CMM) measurements
Sözak, Ahmet; Konukseven, Erhan İlhan; Department of Mechanical Engineering (2007)
In this thesis, the measurement uncertainty of Coordinate Measuring Machine (CMM) is analysed and software is designed to simulate this. Analysis begins with the inspection of the measurement process and structure of the CMMs. After that, error sources are defined with respect to their effects on the measurement and then an error model is constructed to compensate these effects. In other words, systematic part of geometric, kinematic and thermal errors are compensated with error modelling. Kinematic and geo...
A genetic algorithm for 2d shape optimization
Chen, Wei Hang; Oral, Süha; Department of Mechanical Engineering (2008)
In this study, an optimization code has been developed based on genetic algorithms associated with the finite element modeling for the shape optimization of plane stress problems. In genetic algorithms, constraints are mostly handled by using the concept of penalty functions, which penalize infeasible solutions by reducing their fitness values in proportion to the degrees of constraint violation. In this study, An Improved GA Penalty Scheme is used. The proposed method gives information about unfeasible ind...
A genetic algorithmfor structural optimization
Taşkınoğlu, Evren Eyüp; Oral, Süha; Department of Mechanical Engineering (2006)
In this study, a design procedure incorporating a genetic algorithm (GA) is developed for optimization of structures. The objective function considered is the total weight of the structure. The objective function is minimized subjected to displacement and strength requirements. In order to evaluate the design constraints, finite element analysis are performed either by using conventional finite element solvers (i.e. MSC/NASTRAN®) or by using in-house codes. The application of the algorithm is shown by a num...
Citation Formats
E. Koray, “Numerical and experimental analysis of indentation,” M.S. - Master of Science, Middle East Technical University, 2005.