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SUMMARYA general method for shape characterization of two‐dimensional (2‐D) microscopical particles is presented. The proposed procedure based on Fourier analysis techniques can be regarded as a generalization and further development of methods described in the literature. The geometry of the particles is characterized by a set of shape functions which is invariant under translation, rotation and dilation. Shape descriptors generated from the Fourier coefficients are used for shape evaluation. Similarity between particles has been evaluated using an appropriately defined distance measure. The method is demonstrated by an application using a collection of 2‐D objects.

The paper deals with the mass optimization of gear pairs. The proposed material science based selection strategy uses an extended version of Ashby model, where the minimum value of mass as function of material parameters and density can be calculated. Comparative analyses have proved that applying the method proposed, various gear materials can be classified and ranked. It could be concluded that case or induction hardened steels and titanium alloys with appropriate surface treatment are the best solutions for high quality gear materials. The presented relationships for material parameters and geometry of gears help empirical or heuristic selection of proper materials.

This paper introduces a new method for the characterisation of the boundary of diffuse and local necking based on DIC measurements during tensile tests. A series of images illustrate the extension of diffuse necking and show the occurrence of local necking as well. The evaluation of strain distribution gives the exact description of processes using both time dependent and non-dependent methods.

Kinetic models of new types are suggested which are designated primarily to predict the progress of non-isothermal transformations occurring during rapid heating and cooling in alloys. A common feature of each model outlined is that it takes into account not only the varying temperature but also the rate of temperature change on the transformation rate of the process. The two models represented by differential equations are generated by using the concept of virtual kinetic parameters, which can be determined from non-isothermal experiments only. A key property of the virtual parameter "p" involved in the transformation rate equations is that it quantitatively characterizes the temperature rate dependence of the non-isothermal reaction.