Development of design principles for form-fit joints in lightweight frame structures

Based on fundamental technological investigations, alternative joining strategies using electromagnetic forming (EMF) for the flexible production of lightweight frame structures are developed in the collaborative research project SFB/TR10. The results of these investigations will also be used to create general design principles for the joining process itself as well as for the joining zone. The focus of this article will be on dominating form-fit joints of aluminum frame structures and the parameters which have a significant influence on the strength of those joints. For the development of design principles regarding the joining zone, the groove geometry of the connection elements was varied in terms of size and shape, and the influence of those variations was analyzed. In terms of the joining process itself the effect on the joint strength of different forming pressures for a given groove geometry was also investigated. In the first step these experiments were performed on solid mandrels. In order to reduce the weight of the structure, experiments were then performed with hollow connection elements and similar groove geometries to analyze how the reduced stiffness of those elements affected the strength of the joints

What is damaging the kidney in lupus nephritis?

Despite marked improvements in the survival of patients with severe lupus nephritis over the past 50 years, the rate of complete clinical remission after immune suppression therapy i

Threshold behaviour of L3−M4,5M4,5\mathrm{L_3 - M_{4,5}M_{4,5}} Auger transitions in 4d metals

The energy distribution of Auger electrons is strongly modified if the exciting photon energy is varied in the threshold region of the respective inner-shell hole. Resonant inelastic scattering theory predicts this peculiar behaviour which is characteristic of the one-step transition from the initial ground to the final scattering state. This is experimentally studied for the L3 - M4,5M4,5 Auger transition in solid Ru, Rh, Pd, and Ag. For the open d-shell metals strong, dispersing resonance lines are observed around threshold. In the case of Ag, however, sub-threshold excited spectra reveal a continuous electron distribution, highly asymmetric and modulated by the density of unoccupied states. Above threshold it gradually evolves into the characteristic Auger line