Search

Automation of processes related to design and manufacturing is one of the essential goals of most manufacturing companies. The use of modern computer-aided design systems CAD allows partial automation of such processes. The parametric model can be built in some CAD systems. In the parametric model, selected dimensions are treated as control parameters. By changing the values of these parameters, we can control the remaining geometrical dimensions of the model. These dimensions can be associated with linear control parameters using mathematical relationships. Parameterization allows you to associate a geometric model with a mathematical model and allows you to automatically make changes to all elements associated with the currently modified parameter. When working on a non-parameterized model, the changes in the modelled object must be applied separately for each part and subassembly of which it is composed. In a parametric model, changing one parameter entails changes in other parameters dependent on it. Parameterization of the model allows its use for further modification of the designed structure related to customer requirements, even for that very complex, as well as accelerating the design process itself. The article presents a three-dimensional geometric model of a boat davit created with the use of the Siemens NX 9.0 software. In the work, the geometry of the crane model was parameterized for the assumed values of its height and reach. As a result of parametric modelling, the values of the individual geometric dimensions of the device’s structure elements and their mass were obtained. It was justified that thanks to the use of parameterized models, the time of design and construction processes can be significantly reduced, which makes the process more efficient.

Aluminum alloy AW-7020 is characterized by high fatigue strength. It is used primarily in welded constructions, which should be characterized by high strength and resistance to cyclically variable operational loads. They have found wide application in light welded ship constructions, bridge-carrying elements, cranes, hoists, vehicles, roof beams in roof constructions, and security barriers. The paper attempts to determine the influence of selected types of applied heat treatment on the structure and hardness of the AW-7020 alloy used in the shipbuilding industry. Heat treatment processes have been described in the aspect of improving the mechanical and strength properties of the tested alloy and its impact on ductility. Several supersaturation and aging sequences were used in the course of the study. The results of hardness tests of aluminum alloy after its earlier supersaturation and aging (natural and artificial) have been presented. Photographs of internal structures in individual sequences were taken. The obtained hardness measurement results and analysis of structures in individual states were compared with the delivery condition. To illustrate selected heat treatment processes, transient tests were also performed to accurately verify the effect of aging after saturation on hardness and changes occurring in the material structures. The results of the material tests showed that the type of heat treatment after saturation is of significant importance for the hardness and structures of the AW-7020 alloy. As a result of the research, it was proved that the tested alloy obtained in the artificial aging process more favourable strength properties, in a shorter period, compared to the use of the natural aging process.