Steel Mesh-Reinforced Cementitious Composites (SMRCC) (traditionally known as ferrocement) have been in existence for few decades, but have some limitations set on element thickness and number of reinforcing mesh layers and the resulting deflection ductility. Therefore, the author has made an attempt to explore whether deflection ductility will improve in mesh-reinforced cementitious composites (25 mm thick) if discontinuous fibres are added to slab elements. For this purpose, thin slab elements of dimensions 700 mm (length) × 200 mm (width) × 25 mm (thickness) were cast and subjected to four point bending tests. Based on the flexural tests conducted on SMRCC (Control Slab Elements, cast with Steel Mesh Volume of reinforcement, MVr = 0.78, 0.94, and 1.23%) and Hybrid Mesh-and-Fibre-Reinforced Cement Based Composite (HMFRCBC) (Test Slab Elements, combining MVr = 0.78, 0.94 and 1.23% and Polyolefin Fibre Volume fraction, PO-FVf = 0.5‒2.5% of volume of specimens, with 0.5% interval), load-deflection and the deflection ductility index were analyzed. From the flexural load-deflection curves it has been observed that HMFRCBC slabs demonstrate higher flexural load-carrying capacity and deflection ductility when compared to SMRCC slabs. This study shows that higher the polyolefin fibre volume fraction (PO-FVf) from 0.5 to 2.5% (with a 0.5% interval) in HMFRCBC slabs, the higher the flexural deflection ductility. The Deflection Ductility Index (DDI) of HMFRCBC (with 5 layers of mesh and PO-FVf = 2.5%) is 4.5 times that of SMRCC. This study recommends that HMFRCBC can be used as an innovative construction material due to its higher flexural ductility characteristics.

The subject of the work is the analysis of thermomechanical bending process of a thin-walled tube made of X5CrNi18-10 stainless steel. The deformation is produced at elevated temperature generated with a laser beam in a specially designed experimental setup. The tube bending process consists of local heating of the tube by a moving laser beam and simultaneous kinematic enforcement of deformation with an actuator and a rotating bending arm. During experimental investigations, the resultant force of the actuator and temperature at the laser spot are recorded. In addition to experimental tests, the bending process of the tube was modelled using the finite element method in the ABAQUS program. For this purpose, the tube deformation process was divided into two sequentially coupled numerical simulations. The first one was the heat transfer analysis for a laser beam moving longitudinally over the tube surface. The second simulation described the process of mechanical bending with the time-varying temperature field obtained in the first simulation. The force and temperature recorded during experiments were used to verify the proposed numerical model. The final stress state and the deformation of the tube after the bending process were analyzed using the numerical solution. The results indicate that the proposed bending method can be successfully used in forming of the thin-walled profiles, in particular, when large bending angles and a small spring-back effect are of interest.

The reverse bending and straightening test is conducted on wires used for civil engineering applications to detect laminations which can pose a threat to the integrity of the wires. The FE simulations of the reverse bending and straightening of wires with laminations revealed that the reverse bending and straightening test is only effective in revealing or detecting near-surface laminations with lengths from 25 mm located up to 30% of the wire’s thickness and may not be an effective test to detect mid-thickness, near-mid-thickness, and short near-surface laminations with lengths below 15 mm. This is because wires with mid-thickness, near-mid-thickness and short near-surface laminations will pass through the reverse bending and straightening procedures without fracturing and therefore mid-thickness, near-mid-thickness and short near-surface laminations may go undetected. Consequently, other in-line non destructive testing methods might have to be used to detect mid-thickness, near-mid-thickness and short near-surface laminations in the wires.

This article deals with the problem of determining the resistance of end-plate connections. A nonlinear FEM model of the joint was constructed in order to predict its carrying capacity. A standard code procedure was done as well. The analyses have been done to assess atypical end-plate joints designed and constructed as a part of roof structures.

The paper presents the results of preliminary research on the use of silica sands with hydrated sodium silicate 1.5% wt. of binder for the performance of eco-friendly casting cores in hot-box technology. To evaluate the feasibility of high quality casting cores performed by the use of this method, the tests were made with the use of a semiautomatic core shooter using the following operating parameters: initial shooting pressure of 6 bar, shot time 4 s and 2 s, core-box temperature 200, 250 and 300 °C and core heating time 30, 60, 90 and 150 s. Matrixes of the moulding sands were two types of high-silica sand: fine and medium. Moulding sand binder was a commercial, unmodified hydrated sodium silicate having a molar module SiO2/Na2O of 2.5. In one shot of a core-shooter were made three longitudinal samples (cores) with a total volume of about 2.8 dm3. The samples thus obtained were subjected to an assessment of the effect of shooting parameters, i.e. shooting time, temperature and heating time, using the criteria: core-box fill rate, bending strength (RgU), apparent density and surface quality after hardening. The results of the trials on the use of sodium silicate moluding sands made it possible to further refine the conditions of next research into the improvement of inorganic warm-box/hot-box technology aimed at: reduction of heating temperature and shot time. It was found that the performance of the cores depends on the efficiency of the venting system, shooting time, filling level of a shooting chamber and grains of the silica matrix used.

The paper presents results of bend tests at elevated temperatures of aluminium alloy EN AC-44200 (AlSi12) based composite materials

reinforced with aluminium oxide particles. The examined materials were manufactured by squeeze casting. Preforms made of Al2O3

particles, with volumetric fraction 10, 20, 30 and 40 vol.% of particles joined with sodium silicate bridges were used as reinforcement. The

preforms were characterised by open porosity ensuring proper infiltration with the EN AC-44200 (AlSi12) liquid alloy. The largest

bending strength was found for the materials containing 40 vol.% of reinforcing ceramic particles, tested at ambient temperature. At

increased test temperature, bending strength Rg of composites decreased in average by 30 to 50 MPa per 100°C of temperature increase.

Temperature increase did not significantly affect cracking of the materials. Cracks propagated mainly along the interfaces particle/matrix,

with no effect of the particles falling-out from fracture surfaces. Direction of cracking can be affected by a small number of

agglomerations of particles or of non-reacted binder. In the composites, the particles strongly restrict plastic deformation of the alloy,

which leads to creation of brittle fractures. At elevated temperatures, however mainly at 200 and 300°C, larger numbers of broken,

fragmented particles was observed in the vicinity of cracks. Fragmentation of particles occurred mainly at tensioned side of the bended

specimens, in the materials with smaller fraction of Al2O3 reinforcement, i.e. 10 and 20 vol.%.

The paper presents results of Ti-addition to High Chromium Cast Iron (HCCI) on the structure and selected mechanical properties. For this

study casted two sets of cylinders with dimensions ø20 mm, ø15 mm x 250 mm, for the High Chromium Cast Iron (HCCI) and with the

4% by mass Ti-addition. Melts were performed in the induction furnace crucible capacity of 15 kg. During the heats the cup with installed

S type thermocouple was poured to record the cooling curves. The cylinders were subjected to the static bending strength test. Samples for

the test microstructure and Rockwell hardness were cut from the cylinders. The study shows that the addition of titanium had an impact on

the structure and thus the properties of High Chromium Cast Iron (HCCI). In subsequent studies, through an appropriate choice of

chemical composition and proper process control, it is planned to obtain in the structure the titanium carbides TiC and chromium carbides

with type (Cr, Fe)7C3.

The results of investigations of the influence of the matrix grain sizes on properties of cores made by the blowing method are presented in

the hereby paper. Five kinds of matrices, differing in grain size compositions, determined by the laser diffraction method in the Analysette

22NanoTec device, were applied in investigations. Individual kinds of matrices were used for making core sands in the Cordis technology.

From these sands the shaped elements, for determining the apparent density of compacted sands and their bending strength, were made by

the blowing method. The shaped elements (cores) were made at shooting pressures being 3, 4 and 5 atn. The bending strength of samples

were determined directly after their preparation and after the storing time of 1 hour.

For riveted joints with eccentricities of the load path, bending moments referred to as secondary bending are induced under nominally tensile loading conditions. Two simple theoretical models proposed in the literature to estimate the associated bending stresses are evaluated in the paper. Both approaches have been implemented in computer programs and applied to estimate the effect of several variables on the calculated bending stresses in the lap joint. Possibilities of the experimental and numerical verification of the models are also considered. Finally, a correlation between the secondary bending computed by one of the simple models and the observed fatigue properties of riveted specimens, as reported in the literature, is investigated. It is shown that deviations of the experimental results from the theoretical expectations stem from additional to secondary bending factors, like the inhomogeneous load transmission through the joint and the residual stresses induced by riveting process. These phenomena are known to be relevant to the fatigue behaviour of riveted joints, but they are not accounted for by the simple models. A conclusion from the present study is that despite the limitations and approximations inherent in the simple models, they provide reliable estimates of nominal bending stresses at the critical rivet rows and can be utilized in currently used semi-empirical concepts for predictions on the fatigue life of riveted joints.

To study the impact of suspended equipment on the ride comfort in a railway vehicle, a rigid flexible general model of such a vehicle is required. The numerical simulations is based on two different models, derived from the general model of the vehicle, namely a reference model of a vehicle with no equipment, and another model with six suspended elements of equipment mounted in various positions along the carbody. The objective of this paper arises from the observation that the literature does not contain any study that highlights the change in the ride comfort resulting exclusively due to the influence of equipment. The influence of the suspended equipment on the ride comfort is determined by comparing the ride comfort indices calculated in the carbody reference points, at the centre and above the two bogies, for a model with six elements of equipment and a model of the vehicle with no equipment.

Wave motion in pipe bends is much more complicated than that in straight pipes, thereby changing considerably the propagation characteristics of guided waves in pipes with bends. Therefore, a better understanding of how guided waves propagate in pipe bends is essential for inspecting pipelines with bends. The interaction between a pipe bend and the most used non-dispersive torsional mode at low frequency in a small-bore pipe is studied in this paper. Experiments are conducted on a magnetostrictive system, and it is observed that T(0,1) bend reflections and mode conversions from T(0,1) to F(1,1) and F(2,1) occur in the pipe bend. The magnitude of the T(0,1) bend reflections increases with increasing propagation distance and excitation frequency. The amplitude of the mode-converted signals also increases with increasing propagation distance, but it decreases with increasing excitation frequency. Because of their longer bent path, the test signals for a pipe bend with a bending angle of 180X are much more complicated than those for one with a bending angle of 90X. Therefore, it is even more difficult to scan a bent pipe with a large bending angle. The present findings provide some insights into how guided waves behave in pipe bends, and they generalize the application of guided-wave inspection in pipelines.

The paper presents an analysis of the behaviour of bent reinforced concrete beams strengthened with CFRP laminates fixed with adhesive before and after unloading, and more importantly, an analysis of the work of reinforced concrete beams strengthened with pre-stressed CFRP laminates fixed with adhesive. The analyses were based on a moment-curvature model prepared by the author for reinforced concrete beams strengthened under load with pre-stressed CFRP laminates. The model was used to determine the effect of compression with CFRP laminates and their mechanical properties on the effectiveness of strengthening the reinforced concrete beams analysed in this study.