Applied Mechanics and Materials Vol. 724

Abstract: The work presents the aproach of initial moddeling and calculus in order to prepare an finite element investigation of the cardan transmission joint. For this, it is necessary to develop a flexible informational system that would connect the constructive design of cardan transmissions to the technological design within a unitary structure. Due to the typodimensional diversity of cardan transmissions, the design and manufacturing of the various components for a certain application domain (medical aparature, dental and agricultural machines, lifting and transportation machines etc.) has been typified. In order to study the problems that occur in the practice of using cardan transmissions, there has been realised a questionnaire-based descriptive research. We insisted on calculation of the cardan transmission for Dacia 1304/1307.

Abstract: In this paper, we proposed a new algorithm to calculate the temperature field of concrete structures with pipe-cooling system. As we know, the pretreatment of pipe model is hard and the calculation will be time-consuming. However, in this algorithm, the computing information of pipes will be included in the exist nodes of elements, so the workload of pretreatment would be reduced. Meanwhile, the finite element method (FEM) format and the formula of water temperature along pipe have been established in this paper. Iteration was not required in this method, so the computing speed will be improved too. An example has shown that this algorithm can response temperature gradient near the pipe and have good efficiency to calculate temperature field of concrete structures with pipe-cooling system.

Abstract: At the present stage, no detailed specifications and codes about wind effects on low-rise buildings in rural areas were made in Chinese. In order to reduce casualties and property loss due to wind damage, the investigation of wind tunnel experiments were carried out. The results indicate that the influence of purlin and front and rear eaves on wind load should be considered in building design. Because a specific blowing angle of wind would produce the largest wind load in the surface of the house. In the structure design, the value of shape coefficient should be increased to a certain degree and also amplify according to windward and leeward roofs.

Abstract: According to a recent development of environmental geotechnical engineering, geotechnical engineering environment connotation , characteristics, and related disciplines aspects of the relationship are summarized and explained. The definition proposed environmental geotechnology views, a brief analysis of urban construction in common environmental geotechnical problems and propose appropriate countermeasures . Finally, emphasize the potential environmental geotechnology great, to be able to further develop and improve in theory and in practice.

Abstract: The Rumei core wall rockfill dam hydropower station is in Lancang River in the Mangkang county of the Tibet autonomous region with maximum height of 315m and crest length of 666.2m. Due to the high core wall rockfill dam has been more than 300m high, water level sudden drawdown of the unsteady seepage condition shall be taken into consideration, according to the given water level drop speed (5m/d) calculate condition, analysis of the seepage field distribution of the different water level, free surface of different time, each material partition of the dam and foundation soil seepage gradient, etc are given. The results showed that the free surface of the upstream dam shell rockfill body dropping fast than the water level dropping speed of the reservoir. The seepage gradient of the upstream shell is very small, which will not cause adverse effect on the upstream dam slope stability. The free surface of the downstream dam shell rockfill body changes little, which will not cause adverse effect on the downstream of the dam slope stability. As the water level falls, the free surface of the core wall dropping speed is slow, far less than the water dropping speed of the reservoir. In the process of emptying reservoir, the free surface of the core wall remains in a high position, which should cause enough attention.

Abstract: The main dam of the upper reservoir of Zhen'an pumped storage power station in Shaanxi Province, China, is a concrete face rockfill dam with height of 125.90m and crest length of 363.00m. The in-situ drilling and geological prospecting show that the groundwater level is higher than the normal water level in part of the left bank and the reservoir tail, leading to the reversed seepage problem of the groundwater through concrete slab under drawdown condition. Based on the establishment and calculation of the three-dimentional finite element seepage model, the analysis and comparison was made between the overall seepage prevention composed of concrete slab + composite geomembrane and the partial seepage prevention composed of concrete slab + composite geomembrane + vertical grouting curtain [1,2]. The result was found that the seepage gradient requirement was met up by both forms, but due to the prevention of supply from the groundwater in the left bank and reservoir tail, the uplift pressure was formed locally in the overall seepage prevention, whereas such problem did not exist in the partial form. With the extra water supply from the groundwater, the partial seepage prevention works better in terms of leakage. Besides, the design of coarse sand drainage layer is well-served in reducing the water pressure beneath the composite geomembrane on the bottom of the reservoir [3]. It is suggested that the high groundwater should be fully utilized for security and economic benefit. The achievement and experience of this partial seepage prevention design should be taken into consideration for other similar projects.

Abstract: With the vigorous development of China's highway construction, more and more stability problems of loose circle occurred in tunnel project, the deformation characteristics and distribution range of rock loose circle is very complex, which is of urgent need to further study. Based on geological data and construction program of Xi Shi slope tunnel, using the combined method of elastoplastic theoretical calculations and FLAC3D numerical simulation to analyze the distribution range of highway tunnel surrounding rock loose circle, and comparing it with the results of the measurements of surrounding rock deep displacement, thus, it is on the conclusion that grade IV rock loose circle of Xi Shi slope tunnel is in the range between 2.0 to 3.0m. Verifing the reliability of the method, and providing a strong guarantee for the design of support parameters.

Abstract:

Free-form and bionic spatial shells are popular in the area of spatial structures. Scallop-shaped surface is the product of evolution and a kind of spatial shells that can satisfy the mechanical requirements. Based on the scallop-shaped lattice shells, this paper focused on the optimization of geometric parameters. The principle of minimum strain energy was applied to conclude the influence law of the geometric parameters on mechanical properties. Finally the optimal values of geometric parameters were obtained. The results show that the optimization of geometric parameters presents the integrated significance to improve scallop-shaped lattice shells.

Abstract: Focusing on the green renovation project of Shendu Building in Shanghai, China, an evaluation system is developed for the comparison of a variety of seismic control schemes for seismic retrofit of the building. A three-dimensional evaluation model is developed in MATLAB to represent the dynamic features of the structural system of the building, and nine key evaluation indices are defined for the evaluation purpose from a global view of both control efficiency and costs. The complete procedure of designing control schemes based on the retrofitted benchmark structure is presented, which may be helpful for researchers and engineers in easily testing various control schemes by using this evaluation system.

Abstract: Shaking table test is an important means of simulated earthquake in laboratory, slope shaking table test data provide a scientific basis for analysis of dynamic stability and instability mechanism of slopes. Sine vibration table test data processing is different from general frequency domain analysis method, need real-time data processing in time domain. Taking the sine sweep test conditions, which is one of the conditions in "Earthquake landslide and slope prevention and control technology research on shaking table test", as an example. Describes the layout of sensors in shaking table test and the reasons; Sine sweep test load and aim; and listed the steps and methods of the sine sweep test in data processing; Through the processing and analysis of test data identified the vibration frequency of model and shaking table system is 30Hz, damping ratio is 2.06%; Analysis and calculation of the different sections of the slope and position of the amplification coefficient. A methodological guidance for shaking table test and dynamic response analysis of the slope is provided.