Milan Kljajin

University North Koprivnica Croatia EU · University Centre Varazdin Croatia EU

The phenomenon of ductile-to-brittle transition in ferritic steels has been a ubiquitous research challenge for the last 50 years. The characterization of this problem using the fracture mechanics concept, from the earliest studies based on the linear-elastic fracture mechanics to the application of the elastic–plastic fracture mechanics, has becom...

Modelling the dynamic behaviour of elevators with high lifting velocities (contemporary elevators in building construction and mine elevators) is a complex task and an important step in the design process and creating conditions for safe and reliable exploitation of these machines. Due to high heights and lifting velocities, the standard procedures...

Fatigue crack growth through different welded joint regions was investigated, in terms of welded joint geometry and fatigue crack position. In the first phase of investigation, numerical simulation of crack growth in a welded joint made of steel P460NL1 was performed using extended Finite Element Methods (xFEM). Numerical models employed Paris law,...

This research will show the analytical way of determining the remaining life of a welded joint with a fatigue crack initiated in its heat affected zone. The calculation will be divided into two stages, since the fatigue crack propagated through the heat affected zone, and then through the parent material. The analysis will be related to specimens w...

In this paper, the design and calculation of planetary transmission with bevel gears for road vehicles is presented. It must transfer power to the wheels with the possibility that wheels can rotate at different speeds. The basic calculation of transmission is performed for the drive machine, where an internal combustion engine is chosen, and for th...

This work presents a developed mathematical model that transforms functions and functionalities as sets from the functional domain and design elements domain. The sets are interconnected by a matrix model which we called the matrix of function and functionality (MFF). By the MFF model we are searching cross-sections of function and functionality se...

This article gives a detailed description of the development of an experimental sensor beam support with an integrated load cell, in this paper also named a smart support. The smart support is designed as a part of a beam bending experimental apparatus. For small universities, the financial effort needed to equip experimental mechanics labs is cons...

Spur gears have a wide application in the machine-building industry. Machining process primarily selected for these gears is hobbing method with modular hobs, or with Fellows cutters. Other methods which can be applied are profiling using the pull broaches, while the finishing can be done by gear shaving or grinding by the Maag, Niles or Reishauer...

Presented in this work is a study on construction stiffness, based on examination of their neutral lines for various cross-section geometries and different force magnitudes. Investigations were conducted both through numerical simulations and experimentally. The results of numerical simulations indicate that stiffness enhancement reduces deflection...

The paper describes the use of MFF (Matrix of function and functionality) as a tool in product development process. After years of analysis of matrix methods, functions and functionalities of the products, we have developed a matrix tool that is designed for a wide range of engineers to help developing of new products or their parts. The paper pres...

The paper presents the issues with the dynamic analysis of mine elevators used with underground exploitation of raw materials. Dynamic occurrences are particularly emphasized with those elevators due to the fact that they are facilities with extreme heights (up to 2000 m) and lifting speeds (up to 20 m/s) using the steel ropes. It shows the forming...

U e-biblioteci Terminološki rječnici Strune objavljuju se terminološke zbirke koje su nastale kao rezultat pojedinih projekata u okviru programa Izgradnja hrvatskoga strukovnog nazivlja – Struna. Struna je terminološka baza Instituta za hrvatski jezik i jezikoslovlje u kojoj se terminografski i jezično obrađuje nazivlje raznih struka radi stvaranja...

The production of floor coverings, in terms of environmental impact, is a very complex process due to a large number of influential parameters - various chemical emissions, inevitability of waste, a great number of influential physical quantities such as noise and vibration, dust and radiation, energy consumption, recyclability, etc. Interest in th...

The mechanisms are systems of moving parts that perform some function. One of their main advantages is converting the input forces and movements into a desired set of output forces and movements. The mechanism movement simulation is described in this paper. The solution includes calculation of velocities, accelerations and overall performance analy...

This article shows the method of ranking the factors in the study of efficiency and effectiveness of the process of quality management system certification compliant with the requirements of international standard ISO 9001. During the research of efficiency of the quality management systems certification process in enterprises of metal processing i...

The paper presents the method of ranking the factors in the study of efficiency and effectiveness of the quality management system certification process which is aligned with the requirements of international standard ISO 9001. During research on the efficiency of the certification of quality management systems we came to the various influencing fa...

Concern for environment is an important element and obligation in contemporary automobile manufacturing. This paper presents an approach to assess environmental performances of motor vehicles by the application of multi-criteria assessment tools.Within the first part of the paper the multi-criteria problem is presented, with special emphasis on sel...

In order to present new possibilities within preliminary design of product development, the objective of this paper is to present new concepts of modularity within Matrix of Function and Functionality (MFF). Design concept is based on a descriptive matrix which is further based on the generative model and the criteria for describing products, funct...

The concept of the CCHP system (combined cooling, heating and power-combined cooling, heating and electricity generation) is described in this paper. The development of CCHP systems comes from the CHP system (combined heat and power generation), also known as cogeneration. CHP systems generate electricity from fuel combustion, heat as a by-product...

Thin-rim gears are often used in applications where light weight and compact design are demanded. Since the gear rim is more rigid in the area of the gear web, this influences the load as well as the contact stress distribution along the tooth face width. Conventional standard procedures for gear design assume uniform rigidity along the face width...

Electric drive elevators represent a special group of transport machines for vertical lifting of a load with stressed dynamic features. Special attention should be paid to the behaviour of these devices in exploitation, as early as in the projecting phase. The paper shows the process of forming adequate mechanical models for elevators grouped accor...

1847-6996

This paper aimsat showing the possibility of improving the initial phase of design process using the matrix function multi-structured formof products and their requests. The developed matrix model is a tool which by using a mathematical model interconnects functions and technical systems that solve them. This is one of the main differences with reg...

The paper presents the possibilityof solar heating as a way of natural gas savings. Solar heatingis ideally usedinour climate area, considering a large number of sunny days and relatively high average temperatures in Croatia, resulting in higher efficiency of heating systems. The advantage of solar heating, compared to other methods (such as heatin...

With increasing awareness of potentially harmful life-cycle environmental impacts, preserving natural resources, government regulations against disposal of toxic substances in landfills, and the consequent development of markets for recycled components and materials, more options are now available for the disposal of post-use electronic equipment (...

This paper presents model and application of product function matrix and its requests model. Model is implemented in developed computer Web application. With connections and winning parameters relation between Blower matrix and Diffuser matrix is presented and achieved. In this way it is possible to generate complete product function structure stor...

With increasing awareness of potentially harmful life-cycle environmental impacts, preserving natural resources, government regulations against disposal of toxic substances in landfills, and the consequent development of markets for recycled components and materials, more options are now available for the disposal of post-use electronic equipment (...

The article presents a new systematic approach to evaluate kinematic structures of the robot for welding in the application of certain conceptual solutions in different welded forms of product design. Generated conceptual solutions of the welded structure are independent of the eight kinematic structuremodels of the robots. Conceptual solutions of...

A developed model of the first structural shape of the matrix of product function and its requests model have been shown in practice. It relates functions of the product and its requests model, and technical systems that solve them. Functions are described by parameters, determined by physical laws. The technical systems and functions are related a...

The initial design of a rotating seat pedestal contains sheet metal parts and features. The design of sheet metal parts with sheet metal features usually requires adjustment for manufacturing. In this paper we present adjustment of the rotating seat pedestal model performed in a bachelor thesis. The pedestal adjustment is carried out according to t...

In order to contribute to the functional modeling of a product based on the functional synthesis paradigm, this paper sets out to present criteria for defining product functions and functionalities. The product function matrix and its requests model has been developed, by interrelating functions and technical systems. Functions are described in ter...

The paper gives research results on power losses in worm gears, i.e. no-load power losses for different initial temperatures. Two lubricants, intended exclusively for worm gears were used, one mineral oil and the other synthetic oil, both produced by the same manufacturer. Research results are shown in tables and diagram with the possibility of com...

The working parts of worm presses from different manufacturers were collected from oil mills in Croatia, Vojvodina and Bosnia and Herzegovina. The chemical composition, microstructure and hardness were determined, and the wear was examined for the original (imported) and the substituted (domestic) parts. The direct costs of tribological origin are...

Quality management systems (QMS) based on the requirements of ISO 9001 standard have been present for more than twenty years. The audits of the QMS are used to evaluate the level of compliance to the requirements of relevant standards. The objective of this paper is to investigate the non-conformities observed during the quality audits in the imple...

In order to improve the accuracy of three-dimensional printing (3DP), we carried out a set of experiments on two-dimensional (2-D) printed model. The combinations of three main processing factors were considered for every experiment: layer thickness, building orientation and infiltrant type. The results of experiments provided the appropriate aniso...

The primary result of system integration for users in an enterprise should be an easier utilization of system. To support product development process through the Enterprise Resource Planning (ERP) system in small and midsize manufacturing companies we considered integration of selected Product Data Management (PDM) functions. We developed suitable...

This paper presents the management system according to the standard ISO 9001:2000 on the example of High School for Safety in Zagreb. The decision about implementation of management system was made in 2001, and the first activities of School's management were the definition of Quality policy and forming of the work team with QMR as the head for imp...

The work presented here provides a mathematical model for solving the problem of lubrication (calculation of efficiency) of worm gear drives, including a description of the engagement geometry and comprehensive modeling of the worm gear drive lubrication process based on the physical characteristics of the lubricant and the applied materials of con...

nema

In a purpose to support the product development process through the ERP system, an appropriate product model should be accomplished and implemented. The paper represents product model suited for the particular ERP system: ERPINS-M. ERPINS stands as an acronym for the Enterprise Resource Planning ININ Solutions, while M annotates a version of the ER...

The paper analyzes protective layers on the working parts of worm-presses of different producers, i.e. original foreign and domestic substitution parts. Chemical structure examinations, metallographic structure tests, wear effect recordings and hardness measurements have been carried out. The wear resistance of our own welded layers has been experi...

This text describes legal requirements and terms related to implementing of Quality Management System (QMS) at faculties in the Republic of Croatia. All necessary activities and required documentation for implementing QMS are defined. At the end, a review is given of objectives which will be obtained by implementing of QMS at higher education and b...

This paper discusses the essence of ecodesign, respectively three key terms: sustainable development, cleaner production and life cycle management compares traditional product development with ecodesign. The term DFX tools is used to sum up all tools which provide a methodology that is focused on part of a product’s life cycle or focused on one of...

It is a fact that the products of today are not designed for easy dismantling or disassembly. Integrated design, certain fastening and assembly principles and surface coatings, for example, can make it very difficult to disassemble the product and to separate materials into non contaminated groups. Hereafter environmental concerns are requiring tha...

This paper presents the management system according to the standard ISO 9001:2000 on the example of High School for Safety in Zagreb. The decision about implementation of management system was made in 2001, and the first activities of School’s management were the definition of Quality policy and forming of the work team with QMR as the head for imp...

Empirical method for determination of gear box efficiency was applied and test figures were compared with measured results. The losses occuring due to inaccuracies in manufacture and assembly, in coupling, packing and housing elasticity are investigated, to determine the influence ″weight″ of each factor respectively.