Prof. Dipl.-Ing. Dr. techn. Dr. h. c. Wilhelm Schneider

Summary In order to provide a firmer foundation on which some reciprocity theorems in Eshelbian mechanics where established earlier, a nonlinear and then linearized formulation of these theorems is presented. To carry out the required operations a simple two-degrees-of-freedom system was chosen. The analysis led to mostly algebraic expressions which are also illustrated graphically. Readers will be very sad to learn of the mournful death on January 7, 2007, of Prof. Dr. sc. techn. Dr. h. c. George Herrmann. Dedicated to Professor Franz Ziegler on the occasion of his 70th birthday     

Eine Mehrwellenlängenmethode zur röntgenographischen Analyse oberflächennaher Eigenspannungszustände in Keramiken Herrn Prof Dr rer. nat. Hans Neff Zur Vollendung seines 70. Lebensjahres gewidmet

A Multi-Wavelength Method for X-RAy Analysis of Near Surface Residual States in Ceramics Because of the brittleness of ceramics, their near surface materials state is of particular importance with respect to their strength. Besides of surface topography and microstructure, also the residual stress state has to be taken into account. X-ray stress analysis has proved to be the most reliable procedure for the determination of near surface residual stress states in ceramics. Often, however, the residually stressed surface layers are very shallow and, despite the small penetration depth of the X-rays used, only integral values of the existing residual stresses can be measured Consequently, it is difficult to asses the Parameters of the applied Pretreatments which influence the residual stress states. A method is described which works with different X-ray wavelengths for measuring lattice strains of several sets of {hkl}-planes of near surface grains to account for very steep stress gradients Corresponding examples of residual stress determinations on machined ceramic surfaces are presented and discussed.     

Prof. Dr. Menso Folkerts sechzig Jahre

Ohne Zusammenfassung     

Prof. Dr. Geert De Schutter, 2001 Robert L'hermite Medallist

RILEM Bulletin

Prof. Dr. Geert De Schutter, 2001 Robert L'hermite Medallist