Heat treatment processes, due to qualitative requirements for the cast machinery components and restrictions on energy consumption resulting on the one hand from environmental concerns, and on the other hand from a requirements coming from minimization of manufacturing costs, are resulting in searching after a technologies enabling obtainment of satisfactory results, in form of improved mechanical properties mainly, while minimizing (limiting) parameters of successive operations of the heat treatment. Heat treatment of the T6 type presented in this paper consists in operations of heating of investigated alloys to suitably selected temperature (range of this temperature was evaluated on the base of the ATD method), holding at such temperature for a short time, and next rapid cooling in water (20 oC) followed by artificial ageing, could be such technology in term s of above mentioned understanding of this issue. Performed T6 heat treatment with limited parameters of solutioning operation resulted in visible increase in tensile strength Rm of AlSi7Mg, AlSi7Cu3Mg and AlSi9Cu3(Fe) alloys.
The paper summarizes the debate concerning the divine hiddenness argument. First, it presents two versions of the argument that was initially formulated by J.L. Schellenberg and subsequently discussed over the last twenty years and it marks its most important theses. Then the author indicates some possible rebuttals, segregating them according to the challenged premises. Particularly noteworthy, he argues, are these theistic answers that accuse the images of God assumed by the hiddenness argument of excessive anthropomorphism and those that try to point out higher goods justifying divine hiddenness. In conclusion the author claims that the hiddenness argument proves atheism only if by theism one understands theistic personalism. Other positions, such as ultimism or theism of transcendence, are not threatened by the argument.
In this research, nonlinear analysis of composite shear walls (CSWs) with a gap between reinforced concrete wall and steel frame is investigated under cyclic loading by the use of the finite element method (FEM) software ABAQUS. For the purpose of the verification, an experimental test is modelled and comparison of its obtained result with that of the experimental test demonstrates an inconsiderable difference between them; therefore, the reasonable accuracy of the modelling is revealed. Then, effects of different parameters on the behaviour of the CSWs are examined. Gap size between reinforced concrete wall and steel frame, reinforcement percentage, steel sections of beams and columns, and existence of reinforced concrete wall are considered as parameters. It is concluded that change of the parameters affects the ultimate strength, ductility, and energy dissipation of the system. A steel shear wall (SSW) is also modelled and compared with the CSWs. Buckling of the walls is presented as well.
The issues of local stability and ultimate resistance of a continuous beam with thin-walled box section (Class 4) were reduced to the analysis of the local buckling of bilaterally elastically restrained internal plate of the compression flange at longitudinal stress variation. Critical stress of the local buckling was determined using the so-called Critical Plate Method (CPM). In the method, the effect of the elastic restraint of the component walls of the bar section and the effect of longitudinal stress variation that results from varying distribution of bending moments were taken into account. On that basis, appropriate effective characteristics of reliable sections were determined. Additionally, ultimate resistances of those sections were estimated. The impact of longitudinal stress variation and of the degree of elastic restraint of longitudinal edges on, respectively, the local buckling of compression flanges in the span section (p) and support section (s) was analysed. The influence of the span length of the continuous beam and of the relative plate slenderness of the compression flange on the critical ultimate resistance of box sections was examined.