In order to determine fracture parameters of the body and fracture conditions, stress and strain fields in the crack zone should be precisely calculated, especially near the crack tip. These goals can be achieved by performing experiments which are very complicated and expensive. More efficient numerical finite element and boundary element methods yielding the reliable data faster than experiments are usually used for practical calculations. A great number of classical analytical, experimental and numerical investigations are restricted to solving two-dimensional problems by making different assumptions. The results may be uncertain when three-dimensional state is simplified to two-dimensional one. Therefore, it is very important to study the effect of this simplification, in other words, to investigate the influence of three-dimensionality. The dissertation research belongs to the area of numerical fracture mechanics.

In order to determine fracture parameters of the body and fracture conditions, stress and strain fields in the crack zone should be precisely calculated, especially near the crack tip. These goals can be achieved by performing experiments which are very complicated and expensive. More efficient numerical finite element and boundary element methods yielding the reliable data faster than experiments are usually used for practical calculations. A great number of classical analytical, experimental and numerical investigations are restricted to solving two-dimensional problems by making different assumptions. The results may be uncertain when three-dimensional state is simplified to two-dimensional one. Therefore, it is very important to study the effect of this simplification, in other words, to investigate the influence of three-dimensionality. The dissertation research belongs to the area of numerical fracture mechanics.

Research hypothesis The dependence of maximal and submaximal indices of aerobic fitness and cardio respiratory system function on the type of ergometry will change due to specific impact of slow adaptation of the researched athletes. The functional indices of persons of different athletic fitness and sports specialization responsible for general adaptation of the human body to physical loads should vary less performing different continuously increasing loads or constant physical loads compared to those fitness indices which more depend on the adaptation specificity of trained muscles. The aim of the research was to establish the peculiarities of indices of athletes’ aerobic fitness and cardio respiratory system function in dependence on ergometry and the specificity of slow adaptation. Research objectives: 1. To compare maximal and submaximal values of indices of cardio respiratory system function of swimmers and untrained persons during cycling and arm ergometry. 2. To compare maximal values of indices of cardio respiratory system function of athletes in dependence on ergometry and the specificity of slow adaptation. 3. To compare submaximal values of indices of cardio respiratory system function of athletes in dependence on ergometry and the specificity of slow adaptation. 4. To compare the changes in the indices of cardio respiratory system function of athletes in the transitional phases of different constant physical load in dependence on ergometry and the specificity of... [to full text] / Tyrimo hipotezė. Maksimalių ir submaksimalių aerobinio pajėgumo ir vegetacinių sistemų funkcijos rodiklių priklausomumas nuo ergometrijos pobūdžio pakis dėl specifinio tiriamų sportininkų lėtos adaptacijos poveikio. Skirtingo treniruotumo ir sportinės specializacijos asmenų organizmo funkcijos rodikliai, atsakingi už bendrąją organizmo adaptaciją fiziniams krūviams, turėtų mažiau skirtis atliekant skirtingo pobūdžio nuosekliai didinamus ar pastovius fizinius krūvius, negu tie pajėgumo rodikliai, kurie labiau priklauso nuo treniruojamų raumenų adaptacijos specifikos. Tyrimo tikslas - nustatyti sportininkų aerobinio pajėgumo ir vegetacinių sistemų funkcijos rodiklių ypatumus priklausomai nuo ergometrijos ir lėtosios adaptacijos specifikos. Tyrimo uždaviniai: 1. Palyginti plaukikų ir nesportuojančių asmenų maksimalias ir submaksimalias vegetacinių sistemų funkcijos rodiklių reikšmes įvairaus pobūdžio darbe. 2. Palyginti sportininkų maksimalias vegetacinių sistemų funkcijos rodiklių reikšmes įvairaus pobūdžio darbe priklausomai nuo ergometrijos ir lėtosios adaptacijos specifikos. 3. Palyginti sportininkų submaksimalias vegetacinių sistemų funkcijos rodiklių reikšmes įvairaus pobūdžio darbe priklausomai nuo ergometrijos ir lėtosios adaptacijos specifikos. 4. Palyginti sportininkų vegetacinių sistemų funkcijos rodiklių kaitą pereinamosiose pastovaus intensyvumo įvairaus pobūdžio darbo fazėse priklausomai nuo ergometrijos ir lėtosios adaptacijos specifikos. Tyrimo rezultatų... [toliau žr. visą tekstą]