Аннотация. С использованием линейного распределения касательных напряжений в зоне очага пластической деформации со знакопеременными силами трения и условия пластичности Мизеса получены зависимости для определения нормальных напряжений на контактной поверхности при осадке прямоугольной и клиновидной полосы, а также при прокатке полосы. Выполнено сопоставление полученных результатов с известными решениями. Показано, что использование приближенного условия пластичности, записанного в главных напряжениях, приводит к существенному уменьшению расчетных значений технологических нагрузок. Ключевые слова: осадка и прокатка полосы, очаг деформации, зона застоя, контактные напряжения, технологические нагрузки.
The boundary problem in cold strip rolling with plane strip deformation is solved on the basis of the Amontons-Coulomb frictional law for materials whose strengthening is described by the formula σ s /σ s0 = 1 + mε n . When n = 1, solution in quadratures is employed; when n ≠ 1, a power series is adopted. The influence of the parameters m and n of the strain-hardening curve on the position of the strip's neutral cross section and the rolling force is established. Increase in n shifts the strip's neutral cross section in the rolling direction. For materials with the same strengthening coefficient on emerging from the reduction zone, the rolling force increases with decrease in n. The new solution is compared with its predecessors. Note that the difference in the results for the rolling force given by the proposed method and the Tselikov formula increases with decrease in n and with increase in m and λ c . It is 20-30% when n ≤ 0.35 and λ c ≥ 1.3.
The influence of a contact surface shape of the deformation zone during cold rolling of a band on the rolling force subject to parameters of the strain strengthening curve of billet material and band tension has been studied by numerical methods. The comparison of the obtained results and well-known ones allowed one to set that in case of the presense of strain strengthening, the replacement of the arc of contact by the chord resulted in a decrease in calculated force of rolling, whose value depends on the presence of the fore tension and the back tension and parameters of strain strengthening of metal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.