Технологический мониторинг рабочих поверхностей матриц для импульсной штамповки
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Дата
2018
DOI
Науковий ступінь
Рівень дисертації
Шифр та назва спеціальності
Рада захисту
Установа захисту
Науковий керівник
Члени комітету
Видавець
НТУ "ХПІ"
Анотація
Целью работы является разработка теоретических основ мониторинга на основе математического описания процессов формирования, деформирования, упрочняющей обработки и эксплуатации матриц для импульсной металлообработки. Обоснована связь между процессами формирования пластического нагружения и эксплуатационных нагрузок, матриц и их качества возможно в результате определения критериев принятия решений при мониторинге процессов формоизменения тонколистовых заготовок. Использованы модели накопления трещиноватости в процессе пластической деформации. Считается, что приращение трещиноватости при пластической деформации является случайной величиной. По данным о напряженно-деформированном состоянии, а также пластичности металла, задавая вероятность разрушения металла Р, определяется степень использования запаса пластичности или предельная деформация при риске получить разрушение по трещинам с вероятностью Р. При выборе рационального способа упрочнения материала рабочей полости матрицы и метода формоизменения заготовки необходимо также проанализировать: степень теплового воздействия на металл, качество заготовок и литых элементов матрицы, технологические возможности, производительность, степень автоматизации и механизации, экономичность, экологичность. Установлены наиболее существенные факторы, влияющие на жизненный цикл матриц. Рассмотрены кинетический подход для определения параметров упрочняюще-стабилизирующей обработки матрицы и необходимость использования критериев упрочнения. Предложено скалярный параметр повреждаемости в условиях импульсного силового нагружения умножить на коэффициент динамичности. Его значение лежит в пределах 0,05-0,5 и зависит от материала, величины и длительности нагрузки. Предложен способ упрочняюще-стабилизирующей обработки рабочих полостей матриц.
The aim of the work is to develop the theoretical foundations of monitoring based on a mathematical description of the processes of formation, deformation, hardening processing and operation of matrices for pulsed metal working. The connection between the processes of formation of plastic loading and operational loads, the matrices and their quality is possible as a result of the determination of decision criter ia when monitoring the process of forming thin sheets. The most significant factors affecting the life cycle of the dies have been determined. The kinetic approach to determining the parameters of the hardening and stabilizing treatment of the die and the need to use the hardening criteria have been considered. The scalar damage parameter in the conditions of the pulsed force loading is proposed to be multiplied by the dynamic coefficient. Its value lies within 0.05-0.5 and depends on the material size and the duration of the load. On the basis of tasks decision the fluctuation theory a ground over of connection is brought between the processes of strengthening-stabilizing treatment of working cavities of the die is proposed. A method for strengthening-stabilizing treatment of working cavities of the die is proposed. Models of the accumulation of fractures in the process of plastic deformation have been used. It is believed that the increment of fractures during the plastic deformation is a random value. According to the data on the stress -strained state, as well as the plasticity of the metal, setting the probability of the metal failure P, the degree of utilization of the plasticity stock or the ultimate deformation is determined when there is a risk of the fracture of cracks with the probability R. When choosing a rational method of strengthening the die working cavity material and the blank forming method it is also necessary to analyze the following: the degree of thermal effects on the metal, the quali ty of blanks and cast die elements, the technological capabilities, the productivity, the degree of automation and mechanization, the efficiency, the environmental friendliness. The most significant factors affecting the life cycle of the die are determined. The kinetic approach to determine the parameters of the hardening and stabilizing treatment of the die and the need to use the hardening criteria are considered. A scalar damage parameter in the conditions of the pulsed force loading is proposed to be multiplied by the dynamic coefficient. Its value lies within 0.05-0.5 and depends on the material, size and the duration of the loading. A method for a strengthening-stabilizing treatment of the working cavities of the dies is proposed.
The aim of the work is to develop the theoretical foundations of monitoring based on a mathematical description of the processes of formation, deformation, hardening processing and operation of matrices for pulsed metal working. The connection between the processes of formation of plastic loading and operational loads, the matrices and their quality is possible as a result of the determination of decision criter ia when monitoring the process of forming thin sheets. The most significant factors affecting the life cycle of the dies have been determined. The kinetic approach to determining the parameters of the hardening and stabilizing treatment of the die and the need to use the hardening criteria have been considered. The scalar damage parameter in the conditions of the pulsed force loading is proposed to be multiplied by the dynamic coefficient. Its value lies within 0.05-0.5 and depends on the material size and the duration of the load. On the basis of tasks decision the fluctuation theory a ground over of connection is brought between the processes of strengthening-stabilizing treatment of working cavities of the die is proposed. A method for strengthening-stabilizing treatment of working cavities of the die is proposed. Models of the accumulation of fractures in the process of plastic deformation have been used. It is believed that the increment of fractures during the plastic deformation is a random value. According to the data on the stress -strained state, as well as the plasticity of the metal, setting the probability of the metal failure P, the degree of utilization of the plasticity stock or the ultimate deformation is determined when there is a risk of the fracture of cracks with the probability R. When choosing a rational method of strengthening the die working cavity material and the blank forming method it is also necessary to analyze the following: the degree of thermal effects on the metal, the quali ty of blanks and cast die elements, the technological capabilities, the productivity, the degree of automation and mechanization, the efficiency, the environmental friendliness. The most significant factors affecting the life cycle of the die are determined. The kinetic approach to determine the parameters of the hardening and stabilizing treatment of the die and the need to use the hardening criteria are considered. A scalar damage parameter in the conditions of the pulsed force loading is proposed to be multiplied by the dynamic coefficient. Its value lies within 0.05-0.5 and depends on the material, size and the duration of the loading. A method for a strengthening-stabilizing treatment of the working cavities of the dies is proposed.
Опис
Ключові слова
жизненный цикл, пластическая деформация, тонколистовая заготовка, импульсная металлообработка, life cycle, plastic deformation, thin blank, pulsed metal treatment
Бібліографічний опис
Технологический мониторинг рабочих поверхностей матриц для импульсной штамповки / В. В. Драгобецкий [и др.] // Вісник Національного технічного університету "ХПІ". Сер. : Інноваційні технології та обладнання обробки матеріалів у машинобудуванні та металургії = Bulletin of National Technical University "KhPI". Ser. : Innovative technologies and equipment handling materials in mechanical engineering and metallurgy : зб. наук. пр. – Харків : НТУ "ХПІ", 2018. – № 23 (1299). – С. 23-27.