Добірка наукової літератури з теми "Non-detachable connections"

The paper proposes a systematic approach to producing non-detachable connections which is based on unified technical solutions in the field of welding, soldering, gluing and other technologies. The given approach includes not only direct execution of the connection but its designing, preparatory operations and also measures carried out after connection producing. The proposed approach is also based on the principles of the required diversity, feedback, hierarchy and decomposition that ensures high efficiency of the developed technical solutions, possibility for setting-up and successful solution of problems in the field of producing non-detachable connections. In order to ensure a successful realization of systematic approach it is proposed to take into account a number of aspects, including the following: systematic and structural aspect that presupposes determination of internal relations and dependences between elements of the given system and it permits to obtain an overview about internal structure (composition) of the investigated system; systematic and functional aspect that presupposes determination of functions, and the system is created for performing these functions; systematic and purposeful aspect that signifies a necessity of scientific determination of system goals and sub-goals, their harmonization between themselves; systematic and resource aspect that presupposes thorough determination of the resources which are required for system performance and solution of various problems with the help of the system; systematic and integration aspect that presupposes to determine a complex of system qualitative properties which ensure its integrity and specificity; systematic and communication aspect that requires determination of external relations of the given system with others that is its relations with the environment; systematic and historical aspect that permits to determine conditions for creation of the investigated system, its past stages, modern state and also possible prospects of development. New connection designs of combined (hybrid) type have been developed on the basis of the systematic approach and the paper presents examples and classification of such connections.

This paper discusses the development of small boats made of polymeric composites in combination with metal skeleton based on detachable elastic connections. Lock material was polyethylene with hyperelastic properties of an elastomer. Static calculation is performed as per the finite-element method in plane formulation taking into account contact, geometric and physical non-linearity, as well as implementing a step-wise procedure. Design calculation is performed as per the research method approximating the sub-task (quadratic programming). The paper presents calculations for the process of inserting/extracting a rigid bar with round free flange to/from the lock, with determination of maximum responses, strains and stresses of the insert. Variation of geometric parameters yielded a design variant with minimum load on the insert and the same strength properties as the initial design. The study also yielded the analytical design methodology for elastic detachable connections that combines the solutions to non-linear contact problem and the optimization problem.

Innovative activity in the field of engineering and technology, based on the use of best practices, contributes to scientific and technological progress in production. The latest projects in the field of technology significantly increase the technical and economic performance of enterprises. Innovative technical solutions of production nature significantly improve the structure and quality of production. Given the level of the proposed technological changes in the manufacture of threads in through holes, these innovations cover the field of combinatorial and partial. Today mechanical engineering is characterized by mechanization and automation of technological processes, a wide range of products of various parts. Among the non-detachable and detachable joints of parts, the threaded connection is the most common. Simplicity, reliability, the ability to adjust the force with which the conjugate surfaces come into contact, the possibility of repeated cycles of disassembly and assembly, etc., make this type of connection the most commonly used in mechanisms and machines of modern engineering. With the simplicity of the contact pair of threaded joints, where one of them contains the outer and the other the inner screw surface, during their manufacture there are problems that significantly inhibit production. The subject of research of this article is the solution of difficulties of manufacturing of an internal cut in through openings of small diameter by means of a tap. According to various sources, up to 80% of marriage is due to breaking taps. Studies by a group of scientists has found that more than 75% of taps break when the reverse (reverse) stroke of the tap, when the torque reaches its maximum value. The reverse scheme of production of a screw profile of a cutting surface by means of the mechanized devices and their alternative analogs, and also machines of drilling group, is offered.

Bolted joints are widespread in various industries. They are used both in detachable and in non-detachable connections. The main requirement for bolted joints is to ensure the strength of the connection and guaranteed contact pressure on the connected surfaces, i.e. joints, during the operation of the structure. As a rule, their design and calculation do not take into account the contact compliance of surfaces, which is determined by their macro- and microroughnesses. This problem leads to an overestimation of the joint strength and an underestimation of the predicted joint compliance. The study proposes a simple model which makes it possible by calculation to take into account the effect of the roughness of the contacting surfaces on the compliance of the joint without modifying the ANSYS application package. On the example of a flange connection, an experimental verification of the adequacy of the proposed model was carried out.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.02.08 – технологія машинобудування. Національний технічний університет "Харківський політехнічний інститут", Харків, 2018. Дисертація присвячена вирішенню науково-технічної задачі забезпечення якості складання виробів, що мають нероз'ємні з'єднання, шляхом розширення технологічних можливостей і підвищення ефективності використання переналагоджуваних універсальних збірно-розбірних пристосувань (УЗРП) в умовах серійного багатономенклатурного виробництва. Проведено аналіз конструкцій, тенденцій розвитку збірних пристосувань та умов їх екс-плуатації для складання нероз'ємних з'єднань. Встановлено основні критерії оцінки працездатності пристосувань і запропоновано способи з’єднання та фіксації елементів УЗРП для забезпечення максимального рівня збирання компоновок. Обґрунтовано умови силової взаємодії елементів нової конструкції. Отримано аналітичний вираз для еквівалентної жорсткості базових плит, визначено основні геометричні параметри елементів і ступінь їх впливу на міцність та жорсткість пристосувань. Проведено експериментальні дослідження напружено-деформованого стану базових плит УЗРП нової конструкції і підтверджено працездатність з'єднань елементів пристосувань. Розроблено методичні та практичні рекомендації щодо визначення раціональних основних конструктивних параметрів елементів УЗРП і компоновок з них для ефективного оснащення серійного багатономенклатурного виробництва. Економічний ефект від упровадження основних положень роботи у виробництво становить 160 тис. грн.
Thesis for the degree of candidate of technical sciences, specialty 05.02.08 – manufacturing engineering. National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2018. The dissertation is devoted to the solution of scientific and technical problems to ensure the quality assurance of products by having integral connections, expanding technological possibilities and increasing the efficiency of universal Prefabricated devices (UPFD) in the conditions of serial multi-nomenclature production. The analysis of constructions, tendencies development of prefabricated devices development and conditions of their operation for assembling non-detachable joints is carried out. The basic criteria for estimating the adaptability of devices are established, methods of connection and fixing the elements of the UPFD are offered for ensuring the maximum level of assembly of layouts. The conditions of power interaction of elements of a new construction are substantiated. An analytical expression for equivalent rigidity of base plates was obtained, the basic geometric parameters of elements and their degree of influence on durability and rigidity of adaptations were determined. Experimental investigations of the strain-deformed steel of the UPFD base plates of the new design have been carried out and the efficiency of connecting the elements of devices has been con-firmed. The methodical and practical recommendations for defining the rational basic design parameters of the elements of the UPFD and their layout for an effective equipment of a serial multi-unit production are developed. The economic effect of introducing the main provisions of work in production is 160000 UAH.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.02.08 – технологія машинобудування. Національний технічний університет "Харківський політехнічний інститут", Харків, 2018. Дисертація присвячена вирішенню науково-технічної задачі забезпечення якості складання виробів, що мають нероз'ємні з'єднання, шляхом розширення технологічних можливостей і підвищення ефективності використання переналагоджуваних універсальних збірно-розбірних пристосувань (УЗРП) в умовах серійного багатономенклатурного виробництва. Проведено аналіз конструкцій, тенденцій розвитку збірних пристосувань та умов їх екс-плуатації для складання нероз'ємних з'єднань. Встановлено основні критерії оцінки працездатності пристосувань і запропоновано способи з’єднання та фіксації елементів УЗРП для забезпечення максимального рівня збирання компоновок. Обґрунтовано умови силової взаємодії елементів нової конструкції. Отримано аналітичний вираз для еквівалентної жорсткості базових плит, визначено основні геометричні параметри елементів і ступінь їх впливу на міцність та жорсткість пристосувань. Проведено експериментальні дослідження напружено-деформованого стану базових плит УЗРП нової конструкції і підтверджено працездатність з'єднань елементів пристосувань. Розроблено методичні та практичні рекомендації щодо визначення раціональних основних конструктивних параметрів елементів УЗРП і компоновок з них для ефективного оснащення серійного багатономенклатурного виробництва. Економічний ефект від упровадження основних положень роботи у виробництво становить 160 тис. грн.
Thesis for the degree of candidate of technical sciences, specialty 05.02.08 – manufacturing engineering. National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2018. The dissertation is devoted to the solution of scientific and technical problems to ensure the quality assurance of products by having integral connections, expanding technological possibilities and increasing the efficiency of universal Prefabricated devices (UPFD) in the conditions of serial multi-nomenclature production. The analysis of constructions, tendencies development of prefabricated devices development and conditions of their operation for assembling non-detachable joints is carried out. The basic criteria for estimating the adaptability of devices are established, methods of connection and fixing the elements of the UPFD are offered for ensuring the maximum level of assembly of layouts. The conditions of power interaction of elements of a new construction are substantiated. An analytical expression for equivalent rigidity of base plates was obtained, the basic geometric parameters of elements and their degree of influence on durability and rigidity of adaptations were determined. Experimental investigations of the strain-deformed steel of the UPFD base plates of the new design have been carried out and the efficiency of connecting the elements of devices has been con-firmed. The methodical and practical recommendations for defining the rational basic design parameters of the elements of the UPFD and their layout for an effective equipment of a serial multi-unit production are developed. The economic effect of introducing the main provisions of work in production is 160000 UAH.

Abstract Shape Memory Alloy (SMA) based actuator systems provide many advantages compared to conventional actuators and have already successfully established themselves on the market in various applications. The state of the art shows a large number of SMA applications in the field of joining technology. However, these are almost exclusively aimed at providing a reliable, robust but non-detachable connection using the shape memory one-way effect. Approaches to realize a releasable connection for disassembly purposes do not or hardly exist so far. In the present paper it is investigated how shape memory alloys can be used to design releasable snap-fit connectors. Therefore, the state of the art in the field of snap-fit connectors, particularly the systems used in the automotive sector is discussed in order to find potential applications. Beyond that, the functional structure of snap-fit connectors is analyzed to determine which SMA semi-finished products are particularly suitable for this purpose. Different concepts are evaluated and a preferred variant is derived. For detail development, a numerical study will be carried out to determine the influences of various geometric parameters on the performance of the actuator. This is realized using an SMA Finite Element Analysis (FEA) model based on Auricchio’s approach, which is described in detail. Based on these results appropriately preconditioned SMA semi-finished products are produced and experimentally investigated in order to validate the model. Furthermore, several functional models of releasable snap-fit connectors are produced using additive manufacturing processes thus verifying the approach in experiments.