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Using numerical analysis to evaluate the mechanical properties of concrete is an important method emerged in recent years. However, some concepts and simulation methods need to be further investigated. This research used the test specimen for compressive strength of the concrete as the subject of numerical analysis; simulated the load to reach compressive strength and analyzed the stress field. Finally, yield strength of the concrete specimen is proposed.

Numerical analysis was performed for compressive strength of the concrete. Internal defects of the concrete specimen were simulated and compressive strength reduction mechanism was studied. The defects inside of the specimen are stochastic; therefore it is impossible to study the subject with physical material testing. From this study, it is shown that numerical analysis can effectively simulate internal defects and provide an efficient way to study compressive strength reduction.

Numerical analysis was performed for compressive strength of the concrete. Internal defects of the concrete specimen were simulated and compressive strength reduction mechanism was studied because of angle..

Gold box bucket bottom slot hall-type building is a kind of the highest rank traditional architecture in China. Under the horizontal inertia force, post partial pendulum and the weight of roof make it reset, as a result, it formed a phenomenon —it is on high level but does not fall (high tumbler). When stigma swing, then cap block move. When the friction was eliminated between flower arm and cap block, relative displacement occurs and we call it “soft neck role”. "The phenomenon of high tumbler" and "soft neck" .These two factors determine the excellent seismic performance of the lifted building

The objective of this paper is to quantify the influence of internal defect on the multiaxial strength. Numerical analyses are performed for the second and third axial strength of the concrete. The analysis result indicated the existence of defects not only decreases the strength of materials, but also changed the stress state of the specimen.

Removed due to plagiarism.

A numerical implement to simulate the crack propagating process in arch dam and rock base has been put forward. A new remeshing strategy of FEM meshing grid was presented for improving the calculation accuracy and efficiency. In the period of dividing the dam structure and the foundation rock into an appropriate number of discrete subregion (finite elements), the adaptive element was used to divide the original 3-D element into 8 son-elements analogical to its father-elements entirely. Of course the 2-D element was divided into 4 son-elements analogical to its father-elements entirely using the same method. The element shape function was used to solve suspend nodal point. The arithmetic and shape function’s formulation also were put forward. To satisfy the engineering accurate result, the adaptive element was used to divide the son-element or the grandson-element again. In the calculating processor, the arithmetic of adaptive load step was presented. Only one element failures in a load step. So the cracking processor can be found with automatic mesh generation. An arch dam has been as example to validate the method is right and stability. The arithmetic has important theory and utility value.

Frame of the van is the basis for mounting of the other assemblies, by sustaining the various kinds of force and load from the road and the weight, so the strength and stiffness of the frame is the very important on the overall design of the van. This thesis does an analysis and research in accordance with ANSYS, discussing the frames static strength of the warp working status and the torsion working status, and doing an analysis of stiffness. The result of analysis shows that the frames ultimate stress is lower than the ultimate strength of material, satisfy the design demand. But the strength of material is overall higher, so the economic efficiency is low. This thesis is also provided the parameter for the nest step design of stress centralization areas and unreasonable design structure.

Safe analysis of the progressive slide is used to estimate the stability of arch dam. The space stochastic parameters are surveyed through considering the relativity of parameter. The stability reliability analysis can be divided into element, sub-structure or sub-system, system.etc. From element to system calculate abutment’s ability. Sub-structure is composed by elements parallel connection. System is composed by sub-structures in series. The substructure method is applied to study the interaction between arch dam and its abutment. In this paper, the weakness part of abutment was found by cracking analysis of the progressive slide, and the safe evaluation was given.

Based on the normal H-K rheology model, a new rheological model containing fracture elements for concrete or rock cracked body is introduced. The method to ascertain rheology state is put forward. The new rheological model can change to Maxwell or Kelvin model to express the instantaneous failure, delayed failure state and the accelerating segment. The researching failure element method was used to study the crack propagation. Then the cracking elements were studied using rheology mechanics to solve the cracking time. At last a case study was given to validate the method is feasible.

The research presented the mechanical properties under compressive loads of a natural stone masonry. The characterization of the basic materials and different stone masonry prisms are included. Sandstone and low strength lime–cement mortar were used for this experimental work. The morphological characteristics of walls were also taken into account, in order to manufacture prism specimens that were as representative as possible of the Chinese typology. The experimental values were compared with the analytical in different masonry.

Based on more than 30 Km field survey, many samples has been got from sluice pier which is collapsed due to sulfate attack. The microstructure of sample and mineral component of separated material was analysis by X-ray diffraction (XRD) and scanning electron microscope-energy dispersion X-ray analysis (SEM-EDAX). The test shows the failure mechanism is contact dissolution associating sulfate attack. The contact dissolution gave chance to sulfate attack. The concrete expand due to sulfate attack accelerate contact dissolution. So concrete can be failure quickly.

The failure process of hydro structures concrete structure and time and space has stochastic relation. The durability failure mechanism, durability failure type and durability failure mode were presented in the paper which is different from caviling engineering. The relation of durability and resisting ability was studied. Based on credibility theory, service-life of hydro structure concrete member was predicted. and the mend measures to improve durability was put forward.

Copper (Cu) nanoparticles have been electrochemically deposited onto the glassy carbon electrode (GCE) surface by potentiostatic deposition method and then carbon nanotubes (CNTs) was dropped on the nano-Cu modified electrode surface to get a CNTs/nano-Cu/GCE electrode. The CNTs/nano-Cu/GCE has shown much higher electrocatalytic activity than the CNTs/GCE towards the oxidation of dopamine (DA) and uric acid (UA) in a phosphate buffer solution (pH 6.9). It can be applied to determine DA and UA with satisfactory results.

Regional safety alarm system is a security system widely used in enterprises and institutions, residential districts and office buildings, which has a complex structure and higher costs. This design is mainly to use SCM and some simple photoelectric sensors to achieve a regional safety alarm system with high reliability and low misoperation, and its size can be easily extended according to user needs.

Through a series of tests of thermal capability to rubber concrete, we get the adiabatic temperature rise curve and hydration temperature curves with different amount rubber in concrete. It revealed the relationship between amount of rubber and thermal conductivity of rubber concrete. Large rubber pieces should be used to replace coarse aggregate in protection concrete of sluice pier and bridge pier.

Based on the normal H-K rheology model, a new rheological model containing fracture elements for concrete or rock cracked body is introduced. The method to ascertain rheology state is put forward. The new rheological model can change to Maxwell or Kelvin model to express the instantaneous failure, delayed failure state and the accelerating segment. The researching failure element method was used to study the crack propagation. Then the cracking elements were studied using rheology mechanics to solve the cracking time. At last a case study was given to validate the method is feasible.

Based on the normal H-K rheology model, a new rheological model containing fracture elements for concrete or rock cracked body is introduced. The method to ascertain rheology state is put forward. The new rheological model can change to Maxwell or Kelvin model to express the instantaneous failure, delayed failure state and the accelerating segment. The researching failure element method was used to study the crack propagation. Then the cracking elements were studied using rheology mechanics to solve the cracking time. At last a case study was given to validate the method is feasible.

Through more than 30 Km field survey in an important project of diversion water, there were many samples been taken from channel concrete lining and sluice pier to study failure mechanism of concrete due to sulfate attack at low value in soft water. The microstructure of concrete and mineral component of separated material was investigated by X-ray diffraction (XRD) and scanning electron microscope-energy dispersion X-ray analysis (SEM-EDAX). Then the processor of chemic action and physics action was analysis. Engineering situation shows that concrete can be failure quickly due to sulfate attack in soft water. Only one winter the strength of concrete reduced to zero. The test shows the failure mechanism is contact dissolution associating sulfate attack. The contact dissolution makes condition for sulfate attack. The concrete expand due to sulfate attack accelerate contact dissolution. So concrete can be failure in a short period.

Removed due to plagiarism.