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In the present work the degradation of nitrogen oxides (NOx) by concrete paving stones containing TiO2 to be applied in road construction is studied. A kinetic model is proposed to describe the photocatalytic reaction of nitric oxide (NO) in a standard flow laminar photoreactor irradiated with UV lamps. In addition the influence of several parameters that can affect the performance of these stones under outdoor conditions are investigated, such as irradiance, relative humidity and wind speed. The kinetic parameters present in the NO reaction rate are estimated employing experimental data obtained in the photoreactor. The obtained model predictions employing the determined kinetic constants are in good agreement with the experimental results of NO concentration at the reactor outlet.

This paper presents an experimental and numerical study on creasing behavior of corrugated paper boards. Experiments have been carried out on corrugated paper board and its constituent papers. Finite element simulations have been carried out on a plane-strain model, incorporating Hill’s plasticity criterion. The finite element simulations are found to be in good agreement with experimental observations up to initial buckling. The study presented here is intended to help in determining the optimum creasing depth to prevent cracking of paper boards during creasing and folding operations while manufacturing packaging boxes.

Continuum approaches are reviewed which can properly model localised deformations that act as a precursor to final fracture in quasi-brittle materials. Next, one such higher-order damaging continuum model is combined with a stochastic approach to describe the heterogeneity in quasi-brittle materials.

The paper describes modeling of initial anisotropy of wood in the framework of microplane theory. The performance of the proposed model is demonstrated on one numerical example. In the example a 3D finite element analysis of a wooden specimen loaded in tension is carried out at the meso scale. The results are compared with the test results and the comparison shows reasonably good agreement.

Limit analysis has been used for decades in civil and mechanical engineering practice as a means of analyzing structures of materials which with reasonable accuracy can be described as being rigid-perfectly plastic. Such materials include steel, concrete and soils. Traditionally, most attention has been given to the problem which consists of determining the ultimate magnitude of a given set of loads acting on a structure with a given geometry. This problem is relevant when determining e.g. the necessary extrusion pressure in metal forming problems, when evaluating the bearing capacity of reinforced concrete slabs or the stability of slopes, and generally, whenever all information about the structure, except for the ultimate magnitude of the load set, is known. However, in the design of structures the situation is the opposite. Here the loads are known whereas the necessary dimensions, boundary conditions, material strengths, etc. must be determined in such a way that the structure is able to sustain the given loads. Thus, limit analysis embraces two different scenarios, one where everything except the maximal permissible load intensity is known, and one where all that is known is the load intensity.In the paper we consider the latter of these problems with particular reference to the design of sheet pile walls.