Search

In this article, the issue of the Goldak heat source model modification was analysed for the Metal-Cored Arc Welding (MCAW) process utilizing gas mixtures based on different argon, carbon dioxide and oxygen ratios. In order to define the specific dimensions of the Goldak heat source model, bead on plate welding was performed at three heat level inputs. Consequently, a 3D scanning of samples was performed as well as a macrograph analysis for each experiment condition. The acquired results show that both the heat input and shielding gas compositions influence the weld geometry and shape of fusion.

Aquaculture is expanding sector on the global level resulting in higher concerns for its sustainability. Generally, sustainability can be defined as a process of meeting the needs of the present without compromising the ability of future generations to meet their needs, and it is considered to be constituted of three pillars: the economy, society and environment. This work considers environmental pillar of sustainability of mariculture systems, with a goal to investigate effect of alternative powering options in mariculture on its lifetime environmental footprint. In this sense the alternative mariculture system from Koričan at al. (2022) has been considered. This work, as a result of INTEL- MARIC project, conducted at UNIZAG FSB considers set of alternative fuels (LNG, Methanol, Biodiesel) and associated emissions (CO2, NOx, SO, and PM) of the mariculture system. The life-cycle assessment (LCA) indicates that significant environmental benefits are possible in case of alternative mariculture system layouts and by use of alternative fuels like for instance methanol or biodiesel.

The offshore multi-use setting represents a model that minimizes spatial competition and advocates its’ multipurpose. Aquavoltaics represent a system of floating solar panels and aquaculture farms working in synergy, ensuring sustainable and efficient food and renewable energy production. In an offshore multi-use setting in the Adriatic Sea, aquavoltaics could be applied in different ways. An extended literature overview is conducted on the topic to accentuate already existing examples of aquavoltaics in use and propose a conceptual model that would be operable in the Adriatic Sea....

In this paper the authors conducted a numerical investigation of residual stress distribution on two butt-welded plates. Subsequently, they incorporated the obtained residual stresses into a welded model that included a hypothetical semielliptic crack. The stress intensity factors (SIFs) were calculated using the eXtended Finite Element Method (X-FEM). The obtained SIFs results match very well with the analytical results of the API 579-1 standard with the biggest difference being 6.73%. Similar differences can be noticed in the comparison between X-FEM and the results obtained by the conventional Finite Element Method (FEM), where the biggest difference between these two results is 6.75%.

Aquaculture has been the fastest-growing food production sector for decades. Nowadays, it is directed towards economically, socially, and environmentally acceptable production. Mariculture production begins at the sea, in cages, where fish is being kept until the appropriate market weight and size is achieved. There are different ways how it can affect the marine environment. Fish products, feces, medicine, food, and other factors have an impact on the sea quality parameters. Marine pollution considers the presence of undesirable materials in the ocean environment that affect mariculture, affecting the seawater's physical, chemical, and biological conditions. To help prevent and to monitor marine pollution, sensors connected with artificial intelligence, Internet-of- Things, applications, and other software are used. The use of multiparameter probes with different sensors in the sea enables the detection of changes in real-time and instantaneous warning. A mobile application connected to the probe provides information about parameters like salinity, sea temperature, oxygen, depth, pH etc. The goal of the developed mobile application is to prevent more serious marine pollution and impact on the production and environment by monitoring sea conditions, reacting on time in the case of anomalies, recognizing unusual patterns in the parameter value distribution from the existing data, as well as expanding the circle of people who can notice and report possible pollution. An early warning algorithm is being developed based on normal, abnormal, and reference values. This work introduces the development of a mobile app, with the emphasis on the basic requirements of the end-user.

The paper proposes a novel staggered phase-field framework for modelling brittle and ductile fractures in monotonic and cyclic loading regimes. The algorithm consists of two mesh layers (displacement and phase field) and a single special-purpose, user-defined finite element, which controls global convergence of the coupled problem and passing of the solution variables between mesh layers. The proposed algorithm is implemented into FE software ABAQUS. For the problem of high cyclic fatigue, a cycle-skipping scheme is also introduced. The proposed methodology is verified on the usual benchmark examples. Small-strain theory is applied, but it has been demonstrated that extension to large strains is straightforward using only the ABAQUS built-in option. The efficiency and stability of the proposed framework was proven by comparison of computational time and the number of iterations per increment in the RCTRL scheme.

In order to continue the development of mariculture in a sustainable manner, fish farms tend to be relocated to further offshore sea areas. A great number of offshore cage farms has been designed, built and put into use over the last few decades, which implicates only further development in that direction. An overview of existing structures for mariculture installations has been conducted in order to analyse technical characteristics of different cage designs and their applicability to potential off-shore farm locations in the Adriatic sea. An extended SWOT analysis was carried out in order to single out systems with greater application potential taking into account conditions in the Adriatic sea and present fish farming practices. Different options are ranked and a preliminary solution of the regionally applicable fish farming cage is proposed to allow further refinement of conceptual designs taking into account not only the technical features but also other factors. This study discusses technical parameters that must be considered for effective offshore mariculture, which have to be additionally combined with other parameters in order to fully support production.

For centuries, constitutive material behaviour is described by long-established analytical expressions. Such constitutive material models, as well as material constants, have been obtained using many experimental trials conducted over many years throughout history. Traditionally, these expressions have been sufficient to describe classical engineering problems. However, due to increasing exploitation of known materials and usage of new materials with heterogeneous microstructure, there is need for more accurate and better description of the material constitutive behaviour. Several different approaches have been proposed to describe the constitutive behaviour of heterogeneous materials over past few decades, among which the most popular is the multiscale method. Although the results of multiscale numerical simulations are satisfactory accurate, the two-scale calculation is time-consuming and computationally expensive process. For this reason, many homogenization methods (reduced homogenization methods) have been developed that seek to find the optimum between the accuracy of the results and the complexity of the calculation. A robust and efficient method of homogenization with a reduced number of degrees of freedom, based on machine learning, has led to significant acceleration of multiscale modelling. The use of reduced order homogenization to solve multiscale problems has proven to be extremely useful for obtaining a large database that will be used to create neural network-based material models. The present work shows the use of the mentioned methods for numerical modelling of nodular cast iron. Calculations are performed on a nodular cast iron RVE using the clustering, and a large database is obtained for different cases of monotonic loading. This database is used to train the neural networks. The entire analysis is performed assuming small strains and plane strain. Deformations are used as input data for neural networks, while the goal is to accurately predict homogenized stress. Neural networks are made using open-source software TensorFlow and Keras API based on the Python programming language.

Welding is used as primary joining technology in various industries like civil engineering, ship- building and heavy-duty machinery building, etc., where machine components of significant thickness need to be welded together. In recent times, many researchers and companies are trying to improve the efficiency of existing welding processes, which is mostly measured in higher deposition rate of molten metal per unit of time. After improving the efficiency of existing welding processes, is to achieve lower values of tensile residual stresses in the welded joint, or in other words to achieve the highest possible values of mechanical properties of the welded joint. Since lower values of residual stresses are hard to achieve without implementing welding in multiple passes, other procedures should be applied after the welding. The most common technology for reduction of residual stresses is post-weld heat treatment. In order to reduce the costs of the testing, the numerical models of heat treatment will be developed on the basis of obtained experimental data in order to examine each PWHT parameter in detail.

Separated phase field algorithm is derived, for the problems of brittle fracture in monotonic and cyclic loading regime.

Kao i u mnogim drugim područjima, u posljednje vrijeme numeričke simulacije sve više nadopunjuju skupe i vremenski zahtjevne eksperimente. Pritom metoda konačnih elemenata, kao jedna od najčešće korištenih numeričkih metoda, ima nezaobilaznu ulogu u projektiranju i procjeni radnog vijeka inženjerskih konstrukcija. Posebno je to slučaj u analizi konstrukcija složenije geometrije i materijala pri složenijim opterećenjima, gdje rješenja dobivena primjenom inženjerskih normi mogu biti dosta konzervativna. Stoga je preporuka da se za dobivanje optimalne konstrukcije, izrazi iz normi kombiniraju s rezultatima numeričke analize. Težište predavanja je na primjeni naprednih numeričkih metoda temeljenih na metodi konačnih elemenata u projektiranju i procjeni radnog vijeka opreme pod tlakom. U prvom dijelu predavanja prikazat će se primjeri projektiranja opreme pod tlakom primjenom novih normi i numeričke analize. Za posude pod tlakom koje uključuju nerazornim metodama otkrivene pukotine, u drugom dijelu predavanja prikazat će se postupak procjene integriteta, odnosno stupnja opasnosti od loma, što može uvelike doprinijeti pouzdanosti, sigurnosti i procjeni vijeka trajanja.

Mariculture is an ever-growing sector with increasing energy needs. Energy intensity depends on cultured species, production technology, organization, and local conditions. Nowadays, the fluctuations in oil prices significantly affect the energy sector and it is evident that long-term sourcing energy from fossil fuels will not be sustainable. Similar can be noticed for the mariculture sector where (especially in the case of cage-based farms) a high share of fossil fuels is used, but at the same time, the energy cost and corresponding implications for carbon and other emission are drawing much attention. Existing references in the field already consider the integration of alternative power options into mariculture farms, with emphasis on renewable energy sources (RESs), claiming that both environmental and economic benefits are achievable. This paper analyses the effect of price fluctuations of selected alternative energy sources on the economic sustainability of mariculture systems, where the energy needs of a typical mariculture farm and corresponding working vessel in the Adriatic Sea are considered in a long-term framework. The results indicate that share of alternative power sources in mariculture systems can be increased without compromising economic indicators. Therefore, bearing in mind their environmental friendliness compared to diesel, the use of alternative fuels in mariculture systems should be encouraged. Finally, recommendations for the design of energy systems for future mariculture farms are drawn.

Mariculture in the Republic of Croatia has a long tradition and is developing by the year. Commonly cultivated species include finfish, both white and oily, and shellfish. Techniques and tools used in the past have changed over time and the production volume along with it. Fish farmed in Croatia today has found its way to Croatian and foreign markets relatively easily, due to its great quality and high market needs. However, considering the high indentation of the coast and the great seawater quality, the production volume of Croatian mariculture is expected to progress further and this should be associated with relevant regulatory framework. In this paper, the existing regulatory framework that tackles the mariculture sector in Croatia is reviewed together with some additional aspects of the fish farming industry. Also, a review of the current state and economic viability of Croatian mariculture is included. Farmed species and mariculture farm structures are presented in order to complement the production volume interpretation. The possibility of further development is discussed taking into account potential obstacles such as environmental concerns, high energy and fish feed costs, etc.

In recent years, the use of new advanced materials plays an ever-more significant role in modern structures and machine components. In comparison with conventional metallurgy procedures, sintering, also known as powder metallurgy, presents significant advantages. However, the porosity of the sintered materials causes stress concentration, strain localization and damage accumulation in a material microstructure, which can lead to the material failure. Therefore, fracture modelling on the material microscale level is necessary for the reliable behaviour assessment and life-time determination of sintered materials on the macroscale. During recent years, the phase-field (P-F) method has gained huge popularity within the computational fracture mechanics field. It is a diffusive method that regularizes the sharp crack discontinuity within a volume, which is often controlled by some length- scale parameter. In the present paper, a 2D P-F formulation is used for modelling microcrack propagation in heterogeneous and homogeneous materials. Different porous models are extracted from metallographic images. The heterogeneous materials consist of two constituents: ferrite and bainite. Elasto-plastic material properties of ferrite and bainite are obtained by the sharp instrumented indentation. The numerical results are compared with metallographic images after uniaxial test to observe intra- or transgranular crack formation.

The rapid development of aquaculture production at the global level is the result of higher demand, modernization, and innovation. Simultaneously, the demand for more food production has a big impact on the environmental footprint. The design environment for aquaculture plants becomes ever complex since it is necessary to consider technical, economic, environmental, and social issues. This paper introduces the research background and activities of the INTEL-MARIC (The research center for INTELligent, innovative, environmentally friendly, and sustainable MARICulture) project, that is being implemented at UNIZAG FSB. Within the project, an advanced multidisciplinary research center has been founded, where important problems inherent to the sustainable development of Croatian mariculture are dealt with. The research background of the center associated with the state-of-the-art in the Croatian aquaculture related to energy needs, production, revenue, and environmental impact is elaborated and predictions for future development are discussed. Consequently, a set of technical solutions and methods which should meet future requirements is reviewed.

In recent years, there has been a tendency to increase the efficiency of existing welding processes. This is most commonly done by achieving higher molten metal deposition rates, which is extremely important for welding steel structures of significant thickness. The buried-arc methodology allows the welding of plates up to 30 mm in thickness by only using one pass. There is a lack of data on the applicability of this relatively new welding method and is necessary to investigate this procedure experimentally and numerically. Numerical simulations are increasingly used for predicting residual stress distributions and could replace expensive experimental measurements in the future. In this paper, a prescribed temperature approach was used in order to reduce model preparation and computation time. The obtained results are compared to the previous work of authors using the constant heat flux method for simulating heat input during welding. The influence of strain hardening on residual stress distribution was considered by using bilinear isotropic and kinematic hardening models.

Aquaculture is most rapidly expanding food industry globally, and nowadays practically all marine production takes place not far from the coast. However, coastal zones are becoming increasingly limiting, particularly in tourism- oriented countries like Croatia, which motivates research into use of open sea sites for mariculture production. It is likely that this direction will be associated with higher both capital and operative costs, and therefore design of offshore mariculture should be carefully addressed considering environmental conditions of the target site, technical features of the mariculture farm as well as economic indicators of a whole production chain. There is no clear definition of offshore mariculture, but in this type of activity fish farms are considered as located in deeper and less sheltered waters at some distance away from the coast (definition set by Food and Agriculture Organization of the United Nations (FAO) includes some quantitative indicators), and the cultivated fish stocks are exposed to more naturalistic living conditions with stronger environmental loads (waves & currents), more difficult mooring conditions, and more diverse nutrient flow. There are basically two types of cage structures intended for offshore aquaculture: floating or submersible, where the former ones have been most commonly used up to this stage, while the latter ones are emerging. Before developing the fish farm, important factors to consider are wind and wave conditions, currents, water depth as well as specific seawater parameters desirable for individual species. This part of the overall research within the INTEL- MARIC project deals with mapping of environmental parameters in the Adriatic Sea from the viewpoint of design of offshore floating structures to assess techno-economic viability of offshore mariculture farms, while considerations on physical (temperature, salinity, turbidity…) and chemical (pH, dissolved oxygen…) seawater parameter monitoring will be addressed next steps, Figure 1.

The phase-field (P-F) method is the most promising diffusive approach for modelling fracture phenomena, but it is sensitive on the value of the length-scale parameter [1], and requires the use of high-density mesh as well as high computation costs. This paper presents a length-scale insensitive P-F model. In contrast to the model in [2], where the derivatives of a degradation function and the local part of a crack surface density function with respect to the phase-field at the undamaged state are utilized, we employ the scaling factor of the crack surface density function to obtain length-scale insensitivity. Following ideas from [3], a new family of crack surface density functions and a new softening law concept are introduced, which enable independent calibration of the P-F profile, the stress-strain response and the critical stress. In the conventional Finite Element Method (FEM) framework, a fully broken specimen contains one layer of fully broken elements. To develop this layer, additional spurious fracture energy needs to be dissipated, and the critical energy release rate and the critical force are seemingly increased. To reduce this additional parasitic fracture energy and reduce the mesh density requirements, a discretization by finite elements and finite volumes was utilized in [4]. In this work, a new dual-mesh discretization scheme is proposed, with the primary triangular mesh and the secondary polygonal or triangular mesh.

In the last decade, the phase-field modelling of fracture gained significant popularity, as it is an elegant and versatile numerical tool capable of accurately capturing experimentally observed crack patterns. However, basic brittle fracture models are neither perfect nor universal, their flaws often stemming from the adopted energy decomposition. Models that use spectral splits are sometimes prone to the transmission of shear stress through a crack, while the spherical- deviatoric decomposition can be prone to cracking in compression and to the artificial loss of compressive stiffness. To solve those problems, different models based on directional splits have been proposed. In this contribution, we propose a new approach for decomposing the strain energy, where both the spectral and directional energy split are used, depending on the intensity of the damage in material. Thereby, the spectral-based energy decomposition is dominant for small phase- field values, while at high phase-field values the directional-based energy split becomes more relevant. As a result, material behaviour shortly after the crack initiation is defined by the spectral energy split, while the behaviour preceding the complete material failure is determined by the directional split. The definition of the crack driving force is inspired by the Rankine criterion. The calculation of crack direction is performed as a ‘postprocessing’ of the phase-field, where the smoothing of the phase- field gradient is utilized. To speed up computation, a simple adaptive refinement procedure is utilised. Preliminary results of simple standard benchmark examples as well as problems with complex geometry show that the method results in physically meaningful stress distributions, as the model is capable of simulating crack closure, i.e., the contact between crack surfaces, without producing any spurious stresses.

The paper presents a separated staggered phase field methodology for modelling of brittle fracture. The basic relations of the phase field formulation are derived, along with decomposition of the strain energy. In separated scheme, displacement model is computed separately from the phase field model in concurrent fashion. The transfer of variables among models, loading imposition and incrementation are governed by the head routine. A convergence criterion has been suggested, which is based on the norm-2 of the phase field variable. The framework has been implemented into FE software Abaqus and Fortran via user subroutines. The proposed framework has been verified on the standard benchmark problems. The solutions obtained have been compared to the other staggered schemes found in the literature. It has been presented that separated scheme provides correct solutions and requires shorter computational time.

Sinterirani materijali su u posljednje vrijeme postali neizostavan dio u sustavima prijenosa snage i gibanja. Zbog relativno niskih troškova proizvodnje, visoke iskoristivosti materijala, smanjenja buke i vibracija te ekološke prihvatljivosti sinterirani materijali imaju veliku prednost u odnosu na klasične materijale. Jedan od problema sinteriranih materijala je poroznost zbog koje dolazi do koncentracije naprezanja na mikrorazini što pospješuje nastanak i razvoj oštećenja u materijalu. Dobivenim rezultatima metalografske analize u ovom radu je provedeno numeričko modeliranje procesa deformiranja heterogenog sinteriranog materijala Astaloy Mo+0,2C na mikrostrukturnoj razini za konstitutivne modele oštećenja i elastoplastičnog ponašanja materijala. Analizirane su tri različite gustoće sinteriranih čelika i posebno za svaku gustoću tri različite veličine modela. Dvodimenzionalni heterogeni modeli sastoje se od kristalnih zrna ferita i bainita te pora. Svojstva ferita i bainita su dobivena preko instrumentirane metode utiskivanja. Predprocesiranje, procesiranje i postprocesiranje je provedeno u programskom paketu Abaqus koji se temelji na metodi konačnih elemenata. Nakon numeričke simulacije prikazan je utjecaj različitih veličina modela te utjecaj različitih poroznosti za elastično i elastoplastično ponašanje materijala te za elastoplastično ponašanje materijala s oštećenjem. Rad je koncipiran tako da je dan kratki uvod o metalurgiji praha i sinteriranim čelicima. Nakon toga su opisani konstitutivni modeli ponašanja materijala korištenih u ovom radu. Kratko je opisana instrumentirana metoda utiskivanja na mikrorazini i rekonstrukcija podataka za dobivanje materijalnih svojstava korištenih u ovom radu. Dan je uvid u metodu konačnih elemenata i prikazana je formulacija dvodimenzionalnih elemenata korištenih za numeričku simulaciju. Na kraju je opisan postupak predprocesiranja modela te su analizirani rezultati. Rezultati numeričkih analiza uspoređeni su s eksperimentalnim rezultatima na makrorazini dobivenih putem jednoosnih testova. Na kraju, prema rezultatima dan je zaključak. Sintered materials have recently become an indispensable part of power and motion transmission systems. Due to relatively low production costs, high material efficiency, reduced noise and vibration, and low environmental impact, sintered materials have a great advantage over classic materials. One of the problems of sintered materials is porosity, due to which there is a microlevel stress concentration which promotes the initiation and propagation of damage in the material. Using the obtained results of metallographic analysis, numerical modeling of the deformation process of the heterogeneous sintered material Astaloy Mo+0.2C at the microstructural level was carried out in this work for constitutive models of damage and elastoplastic behaviour of the material. Three different densities of sintered steels were analysed and separately for each density three different model sizes. Two-dimensional heterogeneous models consist of crystalline grains of ferrite and bainite and pores. The properties of ferrite and bainite were obtained through the instrumented indentation method. Preprocessing, processing and postprocessing was performed in the Abaqus software package, which is based on the finite element method. After the numerical simulation, the influence of different sizes and the influence of different porosity for the elastic and elastoplastic behaviour of the material and for the elastoplastic behaviour of the material with damage is shown. The paper is designed in such a way that a short introduction to powder metallurgy and sintered steels is given. After that, the constitutive models of the behaviour of the materials used in this work are described. The instrumented micro-level indentation method and data reconstruction to obtain the material properties used in this work are briefly described. An insight into the finite element method is given and the formulation of two-dimensional elements used for numerical simulation is presented. At the end, the model preprocessing procedure is described, and the results are analysed. The results of the numerical analyses were compared with the experimental results at the macro level obtained through uniaxial tests. Finally, according to the results, a conclusion is given.

Sinterirani čelici su sve češći odabir u modernim konstrukcijama i prijenosnicima snage zbog svojih svojstava i jednostavnosti izrade. Proizvodni troškovi u metalurgiji praha u masivnoj proizvodnji su niži nego kod standardnih lijevanih i kovanih čelika zbog manje mase i iskoristivosti sirovine. Kako je poznato, poroznost i nepravilnosti u mikrostrukturi izazivaju koncentracije naprezanja. Pod utjecajem istog, pojavljuju se trajna oštećenja na mikrorazini, što ima direktan utjecaj na ponašanje materijala na makrorazini. Ispitivanjem materijala na makrorazini utvrđeno je drastično smanjenje materijalnih svojstava s povećanjem poroznosti. S druge strane, prema literaturi s povećanjem poroznosti u sinteriranom materijalu raste i nepravilnost pora, odnosno, kružnost pora opada s povećanjem poroznosti. Zbog toga u radu je provedena numerička analiza metodom konačnih elemenata za pore različitih veličina te je istražen utjecaj oblika pora. Korišteni modeli dobiveni su iz metalografske analize sinteriranog čelika Astaloy Mo+0,2C za slučaj monotonog vlačnog opterećenja i elastičnog ponašanja materijala. Odabrano je 15 modela podijeljenih u 3 kategorije kompleksnosti i skalirano na 4% poroznosti. Na temelju dobivenih rezultata pokazan je utjecaj kompleksnosti i opsega pore na koncentraciju naprezanja. Dobiveni rezultati uspoređeni su s dosad objavljenim istraživanjima. Sintered steels have an increased usage in modern designs and transmission systems because of their properties and simple manufacturing process. Manufacturing costs of powder metallurgy in mass-producing are lower than conventional manufacturing of cast and forged steels because a product is lighter and there is higher raw material usage. As is well known, porosity and irregularities in microstructure cause stress concentrations. The stress concentrations cause permanent microdamage which has a direct influence on the properties of a material on a macro scale. A significant decrease in mechanical properties is observed with the porosity increase. On the other hand, studies showed that with increasing porosity in sintered steel pore irregularities increased, moreover pore circularity decreased. Because of these properties, numerical analysis with the finite element method is conducted for different shapes and sizes of pores. Models used in research are taken from metallography images of sintered steel Astaloy Mo+0,2C for a case of tension of elastic materials. 15 models are considered and distributed in 3 categories by their shape complexity and scaled to 4% porosity. Results of the analysis showed the impact of pore complexity and pore perimeter on stress concentration. Results are compared with up-to-date studies.

Electric resistance welding (ERW) is the welding process that involves passing of an electric current through the components with no filler material being used. In the production of the cross wire welded reinforced meshes corrosion resistance has important role. Every resistance welding causes expulsion of material. Too much expulsion creates welds that can't be adequatly protected against corrosion. If the expulsion amount can be controlled, satisfactory weld appearance can be achiveved. While the weld appearance is an important factor, weld strength can not be ignored. The aim of this reasarch is to find the correlation between welding parameters and the weld strenght in order to obtain the weld with satisfactory appearance and required strength. In this case, two steel wires of the same radii are joined together to form reinforcing wire mesh. Mesh production, where multiple welds are being produced at the same time has been described by both Bushell and Jordan.

A comprehensive hybrid approach to large-scale seismic vulnerability and risk assessment of existing urban areas is presented in this study. The approach combines the advantages of the vulnerability index method in assessing the vulnerability of a large number of buildings with the pushover method, that allows to determine the capacity curves and detect the specific limit states of the buildings. The described methodology is used to calculate seismic vulnerability indexes, damage indexes, critical accelerations for different limit states and seismic risk indexes for the case study Kaštel Kambelovac.

Paper proposes a dynamic model of synchronizer engagement which includes axial dynamics of a synchronizer sleeve and rotational dynamics of synchronizer ring. The proposed model would be useful for transmission design and control strategy development. Model structure is dependent on current sleeve position which defines five phases of synchronizer engagement. The simplified model derived from the full synchronizer model allows for much faster simulation execution time while maintaining all significant effects of synchronizer engagement.

The project “Earthquake risk assessment of the City of Zagreb” is in it's half and so is the project activity development of the building database. Paper highlights efforts made in the database creation and it's importance in the project.

Discrete lattice model [1] has been successfully used for description and representation of fracture processes that include crack formation and propagation. However, this model is limited in its ability to represent elastic continuum properties. In this work we present the procedure for choosing appropriate parameters that lead to correct elastic continuum response of model.