Papers by Keyword: Constitutive Relation

Abstract: The analysis of structural materials, especially the theoretical research, is always a challenge. Starting from the structural characteristics of the material, the theory of full state function about the strength - stiffness - strain that reflects the properties of structural material is established on the basis of the structural state of the material. The full state function is an important method to solve this problem. In order to further analyze the characteristics of the full state function, the full state function, strength theory of the material and the constitutive relation found are first studied. It is found that the full state function can more comprehensively reflect the properties of the structural material. The full state function accommodates the strength theory in the classical elastic-plastic theory. The full constitutive relation of the materials can be derived from the full state function. That is to say, the full state function can unify the strength theory and constitutive relation in the classical theory and can be used for the analysis of the structural materials. The full state function is more than a mere form, because it has explicit physical and mechanical meanings.

Abstract: The brittle failure finite element method is widely used in arch dam safety evaluation, but it also has some problems, the concrete strength criterion is different, the dam failure range is different. This article first introduces brittle failure constitutive relation and three strength criterions, then takes a high arch dam as an example to compute, obtains some conclusions that the relative failure range of foundation plane corresponds to blaxial strength criterion is slightly bigger than the result of uniaxial strength criterion, is almost the same as the result of triaxial strength criterion. Because the influence of the third principal stress is compressed stress to the dam crack is taken into account under multiaxial strength criterion, therefore using multiaxial strength criterion is more reasonable.

Abstract: In order to effectively use Magnetically Controlled Shape Memory Alloy (MSMA) for vibration control in civil engineering structure, the deformation mechanism and dynamic characteristics of the MSMA were studied; research methods apply to the constitutive relation of vibration control in civil engineering structure is given. Based on the study about MSMA vibration controller and its application in structural vibration control in engineering, MSMA in structure vibration control application prospect and development direction are introduced. At the same time, for the difficulties existing in the application are discussed in this paper. The results prove that MSMA materials in structural vibration control are of important value.

Abstract: Shape memory alloy has received widespread attention in seismic areas now, this paper introduce it develop in the field of earthquake in the past 5 years at home, mainly introduce the research in domestic of passive and active control, roughly summarized it in concrete girder bridge design and test, discussing the constitutive relations of SMA ,finally put forward the problems existing and development prospects .It indicate the direction of practical application in the future.

Abstract: An in depth state-of-art review is done on the topic, constitutive relations of masonry under compression. 12 constitutive models of masonry proposed by scholars from home and abroad are presented in the paper. These models can be classified into four types. Merits and drawbacks of each constitutive relation are discussed. Ten typical constitutive relations are selected to make comparisons. Results show that the ascending branch of curves has few differences, major differences occur in the descending branch of curves. Besides, two experimental data are used to analyze the models and results are discussed. Furthermore, some suggestions on this topic in future research are presented.

Abstract: Isothermal compression test at constant strain rate for Cr-77.5Nb alloy were performed on Gleeble simulator with conditions of deformation temperature from 800 to 1200°C and strain rate from 0.001s^-1 to 0.1s^-1. The influence of deformation parameters including temperature, strain rate and strain related with flow stress during hot deformation were investigated and the constitutive relation of Cr-77.5Nb alloy was established by stepwise regression method. The result of error analysis shows that the constitutive relation established has high accuracy and can well characterize the hot deformation behavior of this alloy.

Abstract: On the basis of plastic-elastic mechanics and finite element method, one selected 150m high reinforced concrete chimney was taken as the target in this paper to analyze the mechanical condition of directional demolition blasting, the capsizing time, the internal force of support abutment and constitutive relation of the chimney during directional blasting. A finite element model of the towering reinforced concrete chimney was established through separated modeling method by finite element analysis software LS-DYNA of ANSYS. Results show that the constitutive relation given by this paper conforms to reality. The finite element model of the towering reinforced concrete chimney established by separated modeling method is reasonable. The real overturn process, capsizing location and capsizing length of towering reinforced concrete chimney during directional demolition blasting are agree with that of numerical simulation.

Abstract: Non-linear finite element model of prestressed steel reinforced concrete(PSRC) beams were carried out by using software ABAQUS. The effects of the parameters of non-prestressed reinforcement ratio, prestressed reinforcement ratio, effective prestressed force and non-prestressed tendons yield strength on the ultimate strength and ductility of PSRC beam were investigated. It is found that increase of the tension reinforcement ratio has little impact on the ultimate deflection but can improve the ultimate capacity of PSRC beam. Increase of the prestressed steel ratio can significantly improve the cracking load, stiffness and ultimate capacity of PSRC beam. The effective prestressed force can improve the bearing capacity of PSRC beam.

Abstract: This article describes the research progress and the development situation of soil dynamics. The soil dynamic constitutive model, dynamic test methods and research status of dynamic parameters are mainly discussed. Finally, some existing problems on the study of soil dynamic characteristics are proposed.

Abstract: Frost resistance is one of the most important indexes of concrete durability, therefore it is essential for the research of constitutive relation for concrete after freeze-thaw damage. The constitutive relation for concrete is directly related to the rationality and security of the structural design. The existing research mainly includes experimental and theoretical simulation, and has made several progresses. Based on the summary of the existing constitutive relation for concrete after freeze-thaw damage, this article puts forward its own idea on the development tendency. And it provides reference for the further study of the constitutive relation for concrete after freeze-thaw damage.