Challenge Journal of Structural Mechanics

156-160

Authors: Semih Özmen, Tunç Bahçecioğlu, Özgür Kurç

This study focuses on developing a parallel solution framework for the linear dynamic analysis of large structural models on homogeneous PC clusters. The framework consists of two separate stages where the former is preparing data for the parallel solution that involves partitioning. The latter is a fully parallel finite element analysis that utilizes substructure based solution approach with direct solvers to perform implicit integration. The linear dynamic analysis of a large scale model was performed on a homogeneous PC cluster and the number of computers was varied in order to demonstrate the performance and the efficiency of the overall solution framework. The performance of the implemented framework was also compared with the widely acknowledged parallel direct solver, MUMPS.

168-172

Authors: Emre Ercan, Ninel Alver, Ayhan Nuhoğlu

Masonry is the oldest building technique that still finds wide use in today’s building industries. The variety and natural availability of the materials that is needed for masonry combined with the easiness of the construction, has resulted in usage of masonry for thousands of years. The lack of research and underdeveloped codes in masonry results in poor applications of masonry technique which causes invaluable loss of lives of people in earthquakes. Today modeling of stone masonry structures is still very difficult because of unknown material properties. This study focuses on estimation of the material properties by destructive testing methods (DT) and non-destructive testing methods (NDT) and analysis of a historic stone masonry arch bridge. After visual investigation, the geometry of the structure is determined and 3D model of the structure was generated and meshed for Finite Element Method (FEM). For evaluation of material properties, NDT methods such as; impact-echo and ultrasonic pulse velocity testing methods were used. Schmidt hammer test was applied for estimation of the hardness of the stones. Fallen stone and mortar samples from the bridge were taken to the laboratory and destructive tests applied on them to determine the properties of masonry components. The test results for the materials obtained from the DT and NDT methods were compared with each other. Using these results mechanical properties of the masonry were estimated using standards and codes. The gathered material properties were assigned to FE model and the model was analyzed.

185-191

Authors: Niyazi Özgür Bezgin

Need for elevated railways may arise when capacity of bus transit and light rail transit that share the right of way with roadways becomes insufficient and the cost of railways with dedicated right of ways such as underground railways becomes costly. A similar need arose in the city of Makah and in 2010 an 18-km long; elevated railway transit service began servicing between the districts of Mina, Arafat and Muzdalifah. Today the two-track elevated system serves along the route constructed by posttensioned 25-m long U-sections spanning between piers. This paper presents the analytical studies and the finite element model of an alternative 30-m long pretensioned boxed-section evaluated during the tender stage. Following a comparison with the applied choice, benefits of the U-section with respect to the analyzed alternative will be discussed.

198-201

Authors: Kemal Hacıefendioğlu, Fahri Birinci

This paper presents the seismic response analysis of offshore wind turbines subjected to multi-support seismic excitation by using a three dimensional numerical finite element model considering viscous boundaries. The sea water-offshore wind turbine-soil interaction system is modeled by the Lagrangian (displacement-based) fluid and solid-quadrilateral-isoparametric finite elements. The research conducts a parametric study to estimate the effects of different foundation soil types on the seismic behavior of the offshore wind turbine coupled interaction system. The results obtained for different cases are compared with each other.