Karel Frydrýšek

VŠB-Technical University of Ostrava · Department of Mechanics of Materials

This article deals with the problem of loose materials, i.e., wheat grain, when transported by belt conveyors with cover belts. For the purpose of further research, experimental measurements of the deflections of a conveyor belt with loose material were carried out on a self-built laboratory test device. The mechanical contact between the wheat and...

Anodization coloring of titanium tools or implants is one of the common methods for the differentiation of each application by its size or type. Commercial purity titanium grade 4 plates (50 × 20 × 0.1 mm) were tested to obtain their electrochemical and other technological properties. The coloring process was done using the potential of 15, 30, 45,...

The topic of the article concerns the mechanics of machining plastics and their machined surface. This article deals with measurements and their stochastic (probabilistic) evaluation of the force and moment loading of the machine tools and workpiece. It also deals with the quality of the machined surface in relation to its surface roughness and sur...

This paper evaluates the various approaches to strength and stiffness analysis of fracture osteosynthesis using a headless Herbert screw. The problem has been extensively addressed using several scientific approaches, namely the analytical approach, stochastic approach, experimental approach, and (marginally) using the finite elements method. The p...

Sandwich conveyors are among continuous transport systems used to transport bulk materials over short distances. The principle of their operation deploys the one of classic belt conveyors. However, in contrast to them, they use two parallel conveyor belts, between which the bulk material is transported. The conveyor belts are pressed against transp...

This article focuses on a type of surgical implant used in orthopaedics and traumatology—cannulated femoral nails. Femoral nails are used in medical treatment for purposes of osteosynthesis, i.e., when treating various types of complicated fractures, in this case fractures of the femur. The article investigates cases in which a nail has been implan...

One of the possible ways to transfer the tractive power of a drive unit to the traction element is to use fibre friction. When a steel rope is used as the traction element, there is a transfer of tractive power in the groove created on the perimeter of the rim of the driving rope sheave. The transmission capability of the drive is directly proporti...

The presented article investigates the biomechanics of the calcaneal nail C-NAILTM by numerical calculations and, partially, experimentally. This nail is widely used in trauma and orthopaedics. A numerical model of implants directly interacting with the bone tissue model obtained from CT scans was calculated. The material properties of the bone tis...

This paper represents a multidisciplinary approach to biomechanics (medicine engineering and mathematics) in the field of collum femoris fractures, i.e., of osteosyntheses with femoral/cancellous screws with full or cannulated cross-sections. It presents our new numerical model of femoral screws together with their stochastic (probabilistic, statis...

A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track, which causes crane skewing. The main causes of crane skewing include unevenness of the crane track, unequal loading of the traction drives depending on the position of the crane trolley, slips and d...

Rope elevators, also referred to as traction elevators, have a cabin suspended from a system of ropes. The system of ropes consists of at least two load-bearing steel ropes with six strands or, from the point of view of easier bending, and currently more widespread, ropes with eight strands. Lifting or lowering of the car, run between the guides, i...

This article deals with a new original analytical solution of deformation, force and stress states in wood screw joints up to the limit values of pulling out/breaking the screw. The screws are under tension. The wood-to-screw interaction is effectively simplified by introducing several physical model variants using a tangential elastic non-linear f...

The aim of this paper is to determinate critical (tearing) force. This force is needed to be caused, for cannula and its securing fixation (in this case by tapes), to be torn out from patient’s body, (i.e. applications in medico-chirurgical branches). To determine this quantity, experimental approach was used, in which for more realistic approach r...

We developed recursive procedure, which allows estimation of the part of solar energy accumulated in the Earth´s crust and estimation of the half-time of the heat radiation/accumulation parameter. This kind of parameter can show time during which one half of the accumulated energy is released back to space. The theoretical relationships were verifi...

We developed recursive procedure, which allows estimation of the part of solar energy accumulated in the Earth´s crust and estimation of the half-time of the heat radiation/accumulation parameter. This kind of parameter can show time during which one half of the accumulated energy is released back to space. The theoretical relationships were verifi...

Abstrakt Všechny klimatické modely předpokládají, že na klima na Zemi má vliv aktivita Slunce (sluneční konstanta), avšak že jeho působení je velice krátkodobé díky rychlé tepelné výměně mezi oceánem a atmosférou (IPCC 2015). Důsledkem tohoto předpokladu je jen malá klimatická teplotní citlivost na rychle se měnící aktivitu Slunce. Protože na zákla...

This article represents a multidisciplinary approach to biomechanics (engineering + medicine) in the field of “collum femoris” fractures. One possible treatment method for femoral neck fractures, especially for young people, is the application of cancellous (i.e. lag or femoral) screws (with full or cannulated cross-section) made of Ti6Al4V or stai...

This work has focused on issues from the fields of geophysics and geomechanics, using methods, approaches and experience from applied mechanics. The introduction to the dissertation formulates the general hypothesis that the behaviour of the Earth’s crust is influenced by exogenous factors to a greater extent than has been previously thought. Based...

Paper focuses on biomechanics, specifically on locking cortical bone screws in angularly stable plates used for the treatment of bone fractures in the medical fields of traumatology and orthopaedics. During extraction of titanium-alloy implants, problems are encountered in an effort to loosen some locking bone screws from the locking holes of an an...

This article deals with a simple planar and statically determinate pin-connected truss. It demonstrates the processes and methods of derivations and solutions according to 1st and 2nd order theories. The article applies linear and nonlinear approaches and their simplifications via a Maclaurin series. Programming connected with the stochastic Simula...

The present paper deals with the calculation of stresses on the pipeline system embedded on a flexible substrate which is burdened by a landslide. As well as taking into account the probability of the influences acting on the pipe as wall thickness, and others.

Traditionally, most scientific publications in this field are focused on how atmospheric changes affect the Earth’s climate. This article takes a less traditional view, addressing the issue of how atmospheric phenomena directly affect the geomechanics of the Earth. Measurement and research of seismic activity includes monitoring the magnitude and t...

This article focuses on ring (Ilizarov) external fixators in traumatology and orthopedics. External fixators are used in the treatment of complicated fractures, bone shortening and lengthening, corrections of angular deformities, and similar applications. An engineering/biomechanical point of view represents an essential perspective when taking acc...

This paper deals with the comparison of experimentally measured temper-ature gradients and finite-element-method (FEM) simulations of two heating strate-gies that were used for continuously cast bloom soaking. The temperature gradient between the bloom surface and center was measured by two thermocouples incor-porated directly into the bloom. Scann...

In this paper, the authors draw attention to biomechanics connected with the possibilities of treatment of complicated bone fractures. They present information about their own design, laboratory tests and numerical solutions (i.e. strength analyses and reliability assessments) of the various types of external fixators applied in traumatology and or...

This paper presents theory, experiments and numerical approaches suitable for the solution of straight plane beams rested on an elastic (Winkler's) foundation, including nonlinearities. The nonlinear dependence of the reaction force on displacement in the foundation (i.e. the experimental data) can be described via bilateral linear or bilateral lin...

This paper presents numerical solutions of straight plane beam structures rested on an elastic (Winkler's) foundation. It is a continuation of our previous work (see Part 1 of this article) focused on practical applications and solutions including nonlinearities in the foundation (i.e. bilateral linear, bilateral linear + cubic, bilateral linear +...

We present a new model of lithosphere-plates movement based on three pillars: 1) The thermoelastic wave, which was described first of all by Berger (1975), 2) The ratcheting mechanism, which was described for asphalt buckling and/or lithosphere evolution by J. Croll (2006, 2007), and 3) the solar irradiance energy, as quantified by IPCC (2007). The...

Continuously cast round blooms from vanadium microalloyed steel denoted as 25CrMo4 type are very sensitive to internal defect creation during casting. Further propagation of internal cracks is affected by suboptimal heating preceding the hot rolling process. FEM offers powerful tool for simulation of the temperature gradients and stress-strain beha...

This article shows how the probabilistic SBRA (Simulation-Based Reliability Assessment) Method (i.e. stochastic Monte Carlo approach) is applied to the model of the behaviour of the lithosphere of the Earth (geomechanical model). The main idea is based on the genesis of thermoelastic waves (i.e. influence of our Son) due to thermal expansion of the...

This article deals with analysis of the knee continuous passive motion (CPM) splint used for rehabilitation of patients after surgeries and injuries. CPM splints are used for speeding up the treatment and restoration of the joint mobility and to stop complications caused by immobilization. The goal is to solve kinematic, dynamic, deformation and st...

At first, the doctors mentioned their own medical experience with treatment of complex pelvic injury in patients with polytrauma and give reasons for necessity of early stabilization of pelvic fractures by means of external fixation, especially with continuous hemorrhage into lesser pelvis region and the retroperitoneum. Afterwards, they used damag...

Wide scales of microalloyed steels are sensitive to internal defects, which occur during the continuous casting and/or ingot mold casting. In this paper, it is demonstrated importance of the proper soaking strategy. Defects free blooms may be heated using a wide scale of heating strategies. On the contrary, optimal choice of heating process is nece...

Four models of transverse cut of continuously cast round blooms with and without internal tricuspid defect were used for FEM simulations. The calculations included two different heating strategies (two and four hours) for heating up to 800 °C. Results clearly demonstrates that stress-strain behaviour of the blooms center is preferably influenced by...

The deformation measurement of rock mass in the depth and mathematical modelling solved the old question of Wegener0s theory “What is the main engine for the lithosphere movement?”. The solar energy, which reaches the Earth, is two orders higher than the energy of all earthquakes and volcanoes. Only a small part of the solar energy is accumulated i...

The deformation measurement of rock mass in the depth and mathematical modelling solved the old question of Wegeneŕs theory "What is the main engine for the lithosphere movement?". The solar energy, which reaches the Earth, is two orders higher than the energy of all earthquakes and volcanoes. Only a small part of the solar energy is accumulated in...

This paper is focused on the explanation of a linkage between two different heating strategies and a grow of the internal casting defects, that are already present in continuously cast blooms made from vanadium micro-alloyed Cr-Mo steel. Internal defects initiation and propagation can be associated to unsuitable casting and heating conditions. Smal...

As fire develops Fire Plume occurs. The temperature characteristics of Fire Plume are described as average, axial or in the radial distance from the centerline. Common methods used for the determination of axial temperature of Fire Plume assume standard conditions of the surroundings and do not take into account the existence of an accumulated laye...

This article is focused on the design of external fixators applied in traumatology and orthopaedics. These fixators have been designed in the Czech Republic and they can be used in the treatment of open and unstable (i.e. complicated) fractures of limbs, pelvis and its acetabulum. Two versions (i.e. old and new) are compared and evaluated. Numerica...

In the case of the Cr-Mo based low-alloyed steel hot rolling of square billets from round continuously cast blooms is complicated by the fact that the internal defects are detected during ultrasonic inspection at the end of production process on cooling bed. Final quality of hot rolled billets is influenced mostly by casting speed and overheating t...

Hot rolling of low-alloyed Cr-Mo based steels from square billets from round continuously cast blooms is complicated by fact that inner voids are indicated during ultrasonic inspection at the end of production process on cooling bed. Final quality of hot rolled billets is influenced mainly by casting speed and overheating temperature in a tundish,...

The paper deals with the electrical and mechanical properties of rubber blends filled by single wall carbon nanotubes (SWCNT-0,6 weight %). We have investigated the alternating current resistivity (ACR), real and imaginary part of dielectric constant,and loss factor .The addition of (SWCNT) to a rubber blend decreases ACR and increases constants ,a...

The present work is devoted to the applications of artificial neural networks (ANN) for material design prediction. We have investigated the dependence of the generated mode frequency as a function of a sample thickness and a sample shape of glass laminate samples by electronic speckle interferometry (ESPI). The obtained experimental results for di...

This article is focused on the theory of straight and curved beams on elastic (Winkler's) foundation. For solution of these problems of mechanics, the Finite Difference Method (i.e. Central Difference Method) can be applied. The basic information about finite differences and their application are explained.

There were done some proposal calculations for a new testing machine. This new testing machine is determined for a dynamic fatigue testing of railway axles. The railway axles are subjected to bending and rotation (centrifugal effects). For the right proposition of a new machine is very important to know the basic dynamic characteristics of whole sy...

This paper shows how the probabilistic SBRA (Simulation-Based Reliability Assessment) Method (i.e. Monte Carlo approach) is applied to the model of the behaviour of the lithosphere of the Earth. The method extends our initial work where we created the geomechanical model of the lithosphere. The basic idea was about the genesis of thermoelastic wave...

This paper shows the probabilistic SBRA Method application to the model of the behaviour of the lithosphere of the Earth (i.e climate changes). The method extends our initial work where we created the geomechanical model of the lithosphere. The basic idea was about the generation of thermoelastic waves due to thermal expansion of the rock mass and...

A developing fire is accompanied by the formation and progress of a burnt gas column which is usually labelled as a Fire Plume. One of the basic characteristics of a Fire Plume is temperature. A Fire Plume is usually characterized by a mean temperature, centreline temperature and the temperature in a radial distance from the centreline. A specific...

This paper focuses on the probabilistic numerical solution of the problems in mining, machine industry and biomechanics. Theory and applications of the Simulation-Based Reliability Assessment (SBRA) method are presented in the solution of the hard rock (ore) disintegration process (i.e. the bit moves into the ore and subsequently disintegrates it,...

This paper is focused on the numerical analysis of the hard rock (ore) disintegration process. The computational modelling leads to the mechanical contact problem between the hard rock and the cutting bit. The bit (i.e. excavation tool with a flat frontal side and a conical edge) moves and sinks into the hard rock and subsequently disintegrates it....

This paper is focused on a numerical analysis of the hard rock (ore) disintegration process. There is discussed the possibility of using computational modelling for the mechanical contact problem between the hard rock and a cutting bit. The bit (i.e. an excavation tool with a flat frontal side and a conical edge) moves and sinks into the hard rock...

1. vyd. Na obálce nad názvem: Vysoká škola báňská - Technická univerzita Ostrava, FS 80 výt. Určeno pro posluchače 1. roč. FS

1st ed. Na obálce a v tiráži vročení 2005 30 výt. Nad názvem: VŠB - Technical university of Ostrava, Faculty of Mechanical Engineering Na obálce nad názvem: VŠB - Technical University of Ostrava, Faculty of Mining and Geology

1. vyd. Autoři 2. části: Otakar Krčál, Karel Frydrýšek, Ludmila Adámková 1. část 150 výt., 2. část 200 výt. Část 1 určena pro posluchače 2. roč. FS, část 2 určena pro posluchače 2. r. FS, 2. r. FMMI a FBI

1. vyd. Nad názvem: Vysoká škola báňská - Technická univerzita Ostrava, Fakulta strojní 50 výt. Určeno pro posluchače 1. a 2. roč. navazujícího MSP FS

1. vyd. Název z obálky 80 výt. 1. část. 2009. 154 sloupců Určeno pro posluchače 3. roč. BSP FS, 1. a 2. roč. navazujícího MPS FS

1. vyd. "Obor habilitace: Aplikovaná mechanika" Nad názvem: VŠB - Technická univerzita Ostrava, Fakulta strojní, katedra pružnosti a pevnosti 62 výt.

1. vyd. Nad názvem: VŠB - Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Mechanics of Materials 100 výt. Určeno pro posluchače 1. roč. BSP FS

1. vyd. Název z titulní obrazovky Určeno pro posluchače 3. r. BSP FS, 1. a 2. r. navazujícího MPS FS, doktorandského studia

1. vyd. Nad názvem: VŠB - Technická univerzita Ostrava, Fakulta strojní, katedra pružnosti a pevnosti 55 výt.

1. vyd. Název z titulní obrazovky; označení vyd. z tiráže Nad názvem: Vysoká škola báňská - Technická univerzita Ostrava, Fakulta strojní Určeno pro posluchače 1. a 2. r. navazujícího MPS FS, doktorandského studia

1st edition Název z titulní obrazovky; označení vyd. z rubu tit. obrazovky