New Approach for Modelling of the Welding Processes
The applying of new technologies is connected with considerable outlays to receive the optimal welding regimes, metallographic research of welding seams, joint quality control and other facilities, which can be considerable lowered, using modelling of the welding processes. We propose to use new approach for modelling – analogue modelling, which is based on process investigation, using logical functions. Some practical applying examples of the analogue modelling are offered in this paper. The analogue model of the heat input during resistance welding of wires with coating is described in detail. Using analogue modelling we can solve direct problems of thermal conductivity, it mean that we can predict temperature field, obtained as a result of influence of welding source of heat. The effectiveness of analogue modelling using is proven.
RESEARCH ON THE SURFACE COATINGS INFLUENCE ON FORMATION MECHANISM OF THE RESISTANCE WELDS
The goal of the work is the research of formation mechanism of the spot resistance welds in the case of copper wires with nickel and tin coatings. The existing approaches for investigation of the formation mechanisms of welds of wires with and without coatings are analysed. A new approach for modeling of welding joint formation is offered. The analog model of the heat input during resistance welding of
Application of resource allocation optimisation to provide profitable options for dairy production systems
A linear program (LP) model analysed resource use on a 100 ha dairy farm. A single optimum-profit combination was established for resources which were either optimised or constrained. It was found that, with a fixed herd of 320 milking cows, when production increased from 305 kg milksolids per cow (kg MS/cow) to 415 kg MS/cow, cash profit increased by 65%. This required additional supplements. If, however, feed demand and supply were optimised at 415 kg MS/cow, the LP reduced milking cow number rather than buy in feed to meet the increased feed demand from higher production per cow. At all production levels chosen between 305 and 415 kgMS/cow, it was most economic to dry off and cull cows early in dry summers to optimise feed demand vs. feed grown; use nitrogen (N) fertiliser to avoid a feed deficit only when response rates of better than 10 kgDM to 1 kg N could be expected; not use N for growing supplements to harvest. Pasture cover, within defined constraint levels, provided a buffer for feed demand and supply fluctuations. The study highlights the importance of assessing production, income and cost in an integrated framework to identify the point at which individual resources become limiting.