No abstract

Scanning observation on meso evolution of fracture in concrete is carried out by means of computerized tomography (CT) on uniaxial compressive condition. The cracks in the mortar expansion, in particular, the bond of mortar and aggregate which is key regions of concrete damaged, are drawn out through CT image and CT data, and the destruction process of the concrete can be divided into four stakes, compression, enlargement, the expansion of the CT crack,and destruction. According to the character of CT image，MMD is used to analyze the CT images of the concrete specimens in 4 stages of deformation. The components of the CT images are classified and the spatial distributions of crack or cavity, mortar and aggregate are obtained. The variation process of the relationship between distributions of crack or cavity magnitude and stress are obtained from classification maps. The specimens experienced the process of condensed, volume expansion, crack propagation, coalescence and failure. The method can not only reflect the spatial distribution of the materials but also simplify the following analyses that follow.

The paper discusses general theoretical and practical aspects of the emerging probabilistic and non-probabilistic approaches for uncertainty treatment in finite element analysis. Based on rough set theory, a new methodology for structural reliability computation is presented. The uncertain parameters of structures are expressed by rough variables. The structure reliability index is computed by rough function and metric. It is valid, and efficient in physics and geometry. Examples of practical application are given.

The effective measure of the disorder in a traffic flow has a great significance to improve the traffic condition and reduce the negative impact on environment caused by traffic jams. Since the traffic one-dimension entropy cannot reflect the spatial distribution characteristics, this paper proposed and defined traffic two-dimension entropy that reflected the statistical information of vehicle types and spatial distribution. In order to reflect the actual condition of a road, the weight of space around a vehicle was used in the simulation. The simulation results showed that: traffic two-dimension entropy to quantify and describe the disorder in traffic flow is reasonable and effective.

With the application of space syntax theory in urban planning and architecture designing is growing continuously, the number of the urban spatial configuration models based on space syntax will be more and more. However, the use of these models still lacks of some intelligent retrieval models currently. This paper splits the urban spatial configuration into regular grid structure, and uses visibility segmentation to construct the relationship diagrams and then extracts space syntax variables from each node to form the four-dimensional histogram. Furthermore, this method calculates the similarity among models through the measurement of the histogram distance, thus realizes the retrieval of the urban spatial configuration. Experimental results show that this model has a satisfactory retrieval results.