Damage Assessment of Concrete under Wind-Sand Load

In this paper, a numerical model of wind-sand flow is established to explore the influence of wind-sand flow parameters on the stress state of the concrete. According to the contact mechanics theory, the wind erosion critical pressure of concrete members and the corresponding stress state of concrete are analyzed. A wind erosion damage assessment index based on stress fatigue theory is proposed.

Cavitation erosion damage of self-fluxing NiCrSiB hardfacings deposited by oxy-acetylene powder welding

This paper comparatively investigates the cavitation erosion damage of two self-fluxing NiCrSiB hardfacings deposited via the oxy-acetylene powder welding method. Examinations were conducted according to the procedure given by ASTM G32 standard. In order to research cavitation erosion (CE), the vibratory apparatus was employed. The cavitation damaged surfaces were inspected using a scanning electron microscope, optical microscope and surface profilometer. The hardness of the A-NiCrSiB hardfacing equals 908HV while that of C-NiCrSiB amounts to 399HV. The research showed that the CE resistance of C-NiCrSiB is higher than that of A-NiCrSiB. The results demonstrate that in the case of multiphase materials, like the NiCrSiB hardfacings, hardness cannot be the key factor for cavitation erosion damage estimation whereas it is strongly subjected to material microstructure. In order to qualitatively recognise the cavitation erosion damage of the NiCrSiB self-fluxing hardfacings at a given exposure time, the following factors should be respected: physical and mechanical properties, material microstructure and also material loss and eroded surface morphology, both stated at specific testing time. The general idea for the cavitation erosion damage estimation of the NiCrSiB oxy-acetylene welds was presented.

CLASSIFICATION AND MAPPING OF LAND USE AND SOME SOIL PROPERTIES IN KIRŞEHIR PROVINCE, TURKEY

In this study, land use capabilities, land types and other soil properties of Kırşehir province were classified and analyzed. In the study, 1/25.000 scale digital soil maps obtained from the Ministry of Agriculture and Forestry (Turkey) were used. Numerical data were classified using Arc GIS 10.3.1 software, which is one of the GIS software. As a result of the research; In general, It was observed that IV. class lands were formed in the Kirsehir province IV.class lands were found to be 1658.3 km2 and it was determined that they cover 25% of the total area. It is seen that soil insufficiency is high in Kırşehir province due to slope and erosion damage. Soil insufficiency due to slope and erosion damage was found to be 3520.7 km2 and it was determined that 54% of the total area was exposed to this effect. It has been observed that the land type is generally composed of steppe, bare rocks and rubble. It was determined that the area formed by bare, rocks and debris is 1128.5 km2. It has been determined that the stony soil areas are 1094.2 km2. As a result of the study, classified map outputs related to land uses and some soil properties were obtained. It will be inevitable that this research will provide important database bases for other studies to be carried out in this region in the future.

Theoretical Prediction Method for Erosion Damage of Horizontal Pipe by Suspended Particles in Liquid–Solid Flows

In order to study the erosion of a pipe wall via a liquid–solid suspension flow, a two-phase flow model combined with an erosion forecasting model for multiparticle impact on horizontal pipe wall surfaces was established in this work on the basis of low-cycle fatigue theory. In the model establishment process, the effects of particle motion and material damage were considered, and a simplified method for predicting horizontal wall erosion was obtained. The calculated results showed that the particles impact the wall at a small angle of most liquid flow velocities, causing cutting erosion damage of the wall. The settling velocity and fluctuating velocity of the particles together determine the radial velocity of the particles, which affects the impact angle of the particles. The cutting erosion caused by the small-angle impact of the particles in the pipe is more likely to cause rapid loss of the wall material. Therefore, the pipe wall is usually evenly thinned.