NOVEL METHODOLOGY FOR REAL-TIME STRUCTURAL ANALYSIS ASSISTANCE IN CUSTOM PRODUCT DESIGN

Mass-customization is related to optimizing the balance between flexibility, strongly required by the customer-focused industries and manufacturing efficiency, which is critical for market competitiveness. In the conventional industries, the process of designing, validating and manufacturing a product is long and expensive. Some of the common approaches for addressing those issues are parametric product modeling and Finite Element Analysis (FEA). However, the costs involved are still relatively high because of the very special expertise needed and the cost of the specialized software. Also, the specific design of the product cannot be validated in a real-time, which often leads to making hard compromises between the specific customer requirements and the structural properties of the product in its exploitation. In this paper, we propose the novel methodology for real-time structural analysis assistance for custom product design. We introduce the concept of so-called compiled FEA model, a Machine Learning (ML) model, consisting of dataset of characteristic product parameters and associated physical quantities and properties, selected ML algorithms and the sets of associated hyperparameters. A case study of creating a compiled FEA model for the case of internal orthopedic fixator is provided

BERGSTRÖM-BOYCE VS. HYPERELASTIC RUBBER MODELS IN STRUCTURAL ANALYSIS OF TIRES

New viscoelastic/viscoplastic material models, such as Bergström-Boyce (BB) model, are known to bring advantages in finite element analysis (FEA) of rubber-based components. To test if the same is true in FEA of tires, a study was performed in which the hyperelastic Yeoh model, BB and dynamic Bergström-Boyce (DBB) models were used to characterize the tread of an existing 205/65 R16 tire. Curve fitting results for all material models as well as the results of the footprint and steady state rolling tire analyses are presented in the paper. There are notable differences between the obtained results at higher strain rates, when viscoelastic material behavior is dominant

Usporedba odziva modela pneumatika s detaljnim gaznim slojem i pojednostavljenog modela za analizu kotrljanja pneumatika u stacionarnom stanju

This paper deals with the level of detail that is necessary for representation of tread pattern in finite element tire models. Different methods for creation of tire tread mesh are systematized by two different criteria: the most common approaches and the finite element analysis type. Some of the representative approaches found in literature are given in more detail and their advantages and disadvantages discussed. An example from author’s experience, which describes the creation of finite element tire model with detailed tread for steady-state rolling analysis, is presented. The paper also brings a head-to-head comparison of the response of simplified and detailed tread tire models, subjected to a range of finite element analyses, from footprint analysis at static loading conditions to steady-state rolling cornering analysis.Ovaj rad se bavi razinom detalja koja je potrebna za prikaz šare gaznoga sloja u modela pneumatika namjenjenih analizi primjenom metode konačnih elemenata. Različite metode za izradu mreže konačnih elemenata su sistematizirane po dva različita kriterija: najčešćih pristupa i tipa analize primjenom metode konačnih elemenata. Neki od tipičnih pristupa koji se mogu naći u literaturi opisani su u više detalja i navedene su njihove prednosti i nedostaci. U članku je dat primjer iz iskustva autora, koji opisuje stvaranje modela pneumatika s detaljnim gaznim slojem za analizu kotrljanja u stacionarnom stanju. U radu je također prikazana izravna usporedba odziva pojednostavljenog modela pneumatika i modela s detaljnim gaznim slojem, podvrgnutih nizu analiza, od analize kontakta između tla i pneumatika pod statičkim uvjetima opterećenja do skretanja pri kotrljanju u stacionarnom stanju

Različiti pristupi za kreiranje geometrijskih modela anatomske osi femura i tijela femura

In today\u27s medicine, especially in the field of orthopedic surgery, it is very important to use geometrically accurate and anatomically correct geometrical models of human bones for the pre-operative planning and implants creation. In order to create such models, two new methods for geometrical modeling were developed and presented in this paper. These methods enable creation of femur anatomical axis and femur shaft geometrical models, and they are: GCM (Gravity Center Method), and CPM (Curve Projection Method). Both methods enable creation of geometrical models which are based on data acquired from the medical imaging devices (CT, MRI, X-Ray). The basic difference between these two methods and all the others is in the manner of generating the points through which anatomical axis model (3D curve) passes or goes near. The applied methods are developed considering the natural shape and anatomical landmarks of the femur bone, as well as standard CAD techniques for geometrical modeling which are common in engineering.U današnjoj medicini, osobito u području ortopedske kirurgije vrlo je važno koristiti geometrijski točne i anatomski ispravne geometrijske modele ljudskih kostiju za pred-operativno planiranje i kreiranje implantata. Radi kreiranja takvih modela dvije nove metode geometrijskog modeliranja su razvijene i prezentirane u ovom radu. Ove metode omogućuju kreiranje geometrijskih modela anatomske osi femura i tijela femura i one su: GCM (eng. Gravity Center Method), i CPM (eng. Curve Projection Method). Obje metode omogućavaju kreiranje geometrijskih modela koji se temelje na podacima dobivenih od medicinskih uređaja (CT, MRI, X-Ray). Osnovna razlika između ove dvije metode u odnosu na sve ostale je u načinu generiranja točaka kroz koje anatomska os modela (3D krivulja) prolazi ili je u blizini. Primijenjene su tehnike koje su razvijene uzimajući u obzir prirodni oblik i anatomske značajke femura. kao i standardne CAD tehnike za geometrijsko modeliranje koje su uobičajene u inženjerstvu

TOWARD AN INTEGRATED INFORMATION SYSTEM FOR THE DESIGN, MANUFACTURING AND APPLICATION OF CUSTOMIZED IMPLANTS

The adjustment of products to the needs of customers has been present in various industries for many years. Personalized medicine is a field that has been rapidly developing recently. This kind of medical help mainly implies the use of medications which are adjusted to each patient individually. In this paper, we describe an information system which manages the process of designing and manufacturing personalized products in the area of orthopaedics. The system output comprises patient-adjusted orthopaedic implants. In addition to the process management, the information system ought to enable the process to be adjusted to unexpected situations which may occur in different stages of designing and manufacturing. The information system should also assist doctors and engineers in the decision making process. This aid is realized in the form of the expert system which provides doctors and engineers with advice about defining an appropriate treatment for the patient

Tyre Design and Optimization by Dedicated CAD Tyre Model

Structural optimization by Finite Elements (FE) is proved very effective in tyre design. For that purpose, major tyre manufacturers use in-house applications. An alternative solution, involving dedicated CAD tyre model (DCTM), is here proposed. DCTM concept permits to easily change the FE tyre models, concerning shape and structure, by moving a part of pre-processing from FE analysis to CAD. No special skills regarding CAD or FEA are required. For every new tyre design, only a new DCTM and a corresponding FE model must be built. All subsequent model changes are automatically performed by mapping and translation routines. To test this concept, DTCM models of an existing tyre were created and used within a pilot design study

REVERSE ENGINEERING OF THE MITKOVIC TYPE INTERNAL FIXATOR FOR LATERAL TIBIAL PLATEAU

In orthopaedic surgery it is very important to use proper fixation techniques in the treatment of various medical conditions, i.e. bone fractures or other traumas. If an internal fixation method, such as plating, is required, it is possible to use Dynamic Compression Plates (DCP) or Locking Compression Plates (LCP) and their variants. For DCP implants it is important to match the patient's bone shape with the most possible accuracy, so that the most frequent implant bending is applied in the surgery. For LCP implants it is not so important to match the patient’s bone shape, but additional locking screw holes are required. To improve the geometrical accuracy and anatomical correctness of the shape of DCP and to improve the LCP geometric definition, new geometrical modelling methods for the Mitkovic type internal fixator for Lateral Tibia Plateau are developed and presented in this research. The presented results are quite promising; it can be concluded that these methods can be applied to the creation of geometrical models of internal fixator customized for the given patient or optimized for a group of patients with required geometrical accuracy and morphological correctness

FEM BASED PARAMETRIC DESIGN STUDY OF TIRE PROFILE USING DEDICATED CAD MODEL AND TRANSLATION CODE

In this paper a finite element method (FEM) based parametric design study of the tire profile shape and belt width is presented. One of the main obstacles that similar studies have faced is how to change the finite element mesh after a modification of the tire geometry is performed. In order to overcome this problem, a new approach is proposed. It implies automatic update of the finite elements mesh, which follows the change of geometric design parameters on a dedicated CAD model. The mesh update is facilitated by an originally developed mapping and translation code. In this way, the performance of a large number of geometrically different tire design variations may be analyzed in a very short time. Although a pilot one, the presented study has also led to the improvement of the existing tire design

A procedure for multi-objective optimization of tire design parameters

The identification of optimal tire design parameters for satisfying different requirements, i.e. tire performance characteristics, plays an essential role in tire design. In order to improve tire performance characteristics, formulation and solving of multi-objective optimization problem must be performed. This paper presents a multi-objective optimization procedure for determination of optimal tire design parameters for simultaneous minimization of strain energy density at two distinctive zones inside the tire. It consists of four main stages: pre-analysis, design of experiment, mathematical modeling and multi-objective optimization. Advantage of the proposed procedure is reflected in the fact that multi-objective optimization is based on the Pareto concept, which enables design engineers to obtain a complete set of optimization solutions and choose a suitable tire design. Furthermore, modeling of the relationships between tire design parameters and objective functions based on multiple regression analysis minimizes computational and modeling effort. The adequacy of the proposed tire design multi-objective optimization procedure has been validated by performing experimental trials based on finite element method

Usporedba odziva modela pneumatika s detaljnim gaznim slojem i pojednostavljenog modela za analizu kotrljanja pneumatika u stacionarnom stanju

This paper deals with the level of detail that is necessary for representation of tread pattern in finite element tire models. Different methods for creation of tire tread mesh are systematized by two different criteria: the most common approaches and the finite element analysis type. Some of the representative approaches found in literature are given in more detail and their advantages and disadvantages discussed. An example from author’s experience, which describes the creation of finite element tire model with detailed tread for steady-state rolling analysis, is presented. The paper also brings a head-to-head comparison of the response of simplified and detailed tread tire models, subjected to a range of finite element analyses, from footprint analysis at static loading conditions to steady-state rolling cornering analysis.Ovaj rad se bavi razinom detalja koja je potrebna za prikaz šare gaznoga sloja u modela pneumatika namjenjenih analizi primjenom metode konačnih elemenata. Različite metode za izradu mreže konačnih elemenata su sistematizirane po dva različita kriterija: najčešćih pristupa i tipa analize primjenom metode konačnih elemenata. Neki od tipičnih pristupa koji se mogu naći u literaturi opisani su u više detalja i navedene su njihove prednosti i nedostaci. U članku je dat primjer iz iskustva autora, koji opisuje stvaranje modela pneumatika s detaljnim gaznim slojem za analizu kotrljanja u stacionarnom stanju. U radu je također prikazana izravna usporedba odziva pojednostavljenog modela pneumatika i modela s detaljnim gaznim slojem, podvrgnutih nizu analiza, od analize kontakta između tla i pneumatika pod statičkim uvjetima opterećenja do skretanja pri kotrljanju u stacionarnom stanju