Material toughness becomes more significant material mechanical property, as well as design variable with recent advances of fracture mechanics understanding. Also, toughness is a particularly important parameter for novel structural materials such as high-strength steels. Furthermore, due to the fact that high-strength steels are mainly used in various welded structures, evaluation of welded joint mismatched properties, including toughness, become particularly important. Therefore, the following paper presents investigation results of impact and quasi-static toughness distribution and mismatch on high-strength steels welds. Welded joint's characteristic heterogeneous zones are obtained by mean of real welding and welding simulation. Finally, relation terms between various mechanical properties, including toughness, for further simplified engineering prediction are provided.

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Wood welding technologies have been developed as a new way of timber bonding without any adhesives. Welding of wood is a process where chemical and physical reactions take place. During the process of welding, the surface layers of wood (lignin) melt, due to high pressure and temperature, which is usually generated by mechanical friction of the elements being in contact. Friction can be induced by vibration or by rotation. This paper presents the results of our own research of the influence of the injection direction of wood dowel into surface by observing the dowel embedded force. In the experimental investigation the differences between the direction of penetration changing the profile of the pre-drilled hole, the impact of consumption of the dowel cap and the impact of the bond strength in relation to the angle between axes of penetration and the line of tree rings are observed.

Mechanical properties testing of structural steel welds are well known and standardized. Results of those testing are important information regarding evaluation and qualification of welding technologies. However, using only standardized testing it is not possible to evaluate the weakest part of welds; e.g. coarse-grained heat affected zone, where peak temperature over 1300 °C is reached during fusion welding. Such high temperatures have for consequence significant change and drop of some mechanical properties. Thus, it is important to perform some more sophisticated evaluation and prior preparation of test specimens. Actually, such prior preparation include welding thermo-cycle simulation on test specimen ready for standardized testing. The paper present one combination of testing results, both standardised and sophisticated, for the purpose of more detailed review of mechanical properties of high-strength steel welds with nominal yield strength in the range of 690-890 MPa. Detailed distribution across welds is presented including the following generalised mechanical properties: hardness, strength, toughness. Significant drop of some mechanical properties is observed within coarse-grained heat affected zone, which may require particular attention within everyday engineering practice.

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