This research investigates wave propagation in an elastic half-space with a quadratic nonlinearity in its stress-strain relationship. Different boundary conditions on the surface are considered that result in both one- and two-dimensional wave propagation problems. The goal of the research is to examine the generation of second-order frequency effects and static effects which may be used to determine the nonlinearity present in the material. This is accomplished by extracting the amplitudes of those effects in the frequency domain and analyzing their dependency on the third-order elastic constants (TOEC). For the one-dimensional problems, both analytical approximate solutions as well as numerical simulations are presented. For the two-dimensional problems, numerical solutions are presented whose dependency on the material's nonlinearity is compared to the one-dimensional problems. The numerical solutions are obtained by first formulating the problem as a hyperbolic system of conservation laws, which is then solved numerically using a semi-discrete central scheme. The numerical method is implemented using the package CentPack. In the one-dimensional cases, it is shown that the analytical and numerical solutions are in good agreement with each other, as well as how different boundary conditions may be used to measure the TOEC. In the two-dimensional cases, it is shown that there exist comparable dependencies of the second-order frequency effects and static effects on the TOEC. Finally, it is analytically and numerically investigated how multiple reflections in a plate can be used to simplify measurements of the material nonlinearity in an experiment.

Armenia is going to join the Customs Union of Belarus, Kazakhstan and Russia (the Eurasian Customs Union) in the coming months. The author uses partial-equilibrium model to investigate and calculate trade diversion, trade creation and net welfare effects of accession on the Armenian economy. The thesis concludes that the membership in the customs union would lead to welfare losses and negative static effects. The main reason is the pure trade diversion effect on Armenia resulting from the increased external tariff rate. Adopting the common external tariff of the Eurasian Customs Union would raise the prices of those imported goods which flow from outside the customs union. As the majority of Armenian imports come from outside the Eurasian Customs Union, the increase in import prices would carry high social costs for the Armenian consumers. In addition, the absence of shared border with the customs union member-states substantially diminishes the potential benefits from possible non-tariff barrier facilitation. Therefore, the thesis strongly recommends against the accession.