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Xie D.,Shandong Urban Construction Vocational College | Tang H.,Shandong University
Advanced Materials Research | Year: 2012

In recent years,most existing engineering structures which have approached their normal life span, such as concrete plate, concrete beam etc., Almost all of these architecture structures are subjected to damage due to external loads, initial design defect etc. Structural damage detection and assessment has been becoming a focus of increasing interest in civil engineering field. However,At present, the study on structural damage detection is still at initial stage and the adopted main approaches are theoretical analysis and numerical simulation, but physical models are scarce. This leads to the yielded theories and methods are not sufficiently applicable for practical engineering application. Aiming at this, this paper focuses on developing effective methods of using wavelet and neural networks to detect the damage of elastic thin plate due to their extensive applications in civil engineering. © (2012) Trans Tech Publications, Switzerland. Source

Zhang H.,Shandong Urban Construction Vocational College | Yu S.-Q.,Shandong University | Wang Z.-L.,University of Jinan
Xiandai Huagong/Modern Chemical Industry | Year: 2016

New polyamide-ester diols are synthesized for polyurethanes by the process of aminolysis-alcoholysis-esterification using recycled polyethylene terephthalate(PET) as raw materials. The effect of dosages of PET and other raw materials on the acid values, hydroxyl values and viscosities of the obtained diols is investigated. The optimum dosages for synthesizing the polyamide-ester diols are as follows: 12.5 g of ethanolamine, 27.5 g of recycled PET, 0.30 g of catalyst zinc acetate and 17.5 g of phthalic anhydride. The acid value, hydroxyl value and viscosity of the product synthesized under the optimal conditions are 3.76 mg(KOH)/g, 386.8 mg(KOH)/g and 2 044 mPa·s, respectively. IR analysis of the obtained product shows the formation of polyamide-ester diols. © 2016, China National Chemical Information Center. All right reserved. Source

Chen Y.,Shandong Jianzhu University | Chen Y.,Shandong University | Zhu W.,Shandong University | Wang Z.,Shandong University | Wang W.,Shandong Urban Construction Vocational College
Modern Tunnelling Technology | Year: 2015

In the discontinuous deformation analysis of rock failure (DDARF), it is assumed that the rock mass is reinforced by end-anchored bolts. The study of the rock masses reinforced by full-length anchored bolts is still in its early stages. In light of the equivalent anchoring effect, and considering the variation of mechanical parameters of the rock mass supported by full-length anchored bolts, a method was proposed to perform an anchoring-effect analysis of full-length anchored bolts in DDARF. Based on construction of the Yimeng power station project, and using FLAC software, this paper analyzed the plastic zone of surrounding rocks under three conditions of excavation: no support; support with improved equivalent mechanic parameters; and rock mass support with full-length anchored bolts. Furthermore, the crack development of the rock masses was analyzed by DDARF. The results show that; 1) in FLAC analysis, fewer plastic zones occurred in surrounding rocks under conditions of support with improved equivalent mechanic parameters and those reinforced with full-length anchored bolts compared with excavation with no support, and the calculation results under the conditions of 1.18 times cohesive force and full-length anchoring are matched especially well; and 2) in DDARF analysis, the cracks in the surrounding rocks using anchors with improved mechanic parameters and full-length anchoring are controlled more effectively compared to those in rock masses with no support, with roughly the same development scale and number of cracks. Thus, using the improved equivalent mechanic parameters for anchored rock masses to simulate the full-length anchoring effect in DDARF can not only reduce the complexity of the calculation but also improve its accuracy. ©, 2015, Editorial Office of "Modern Tunnelling Technology". All right reserved. Source

Su Q.,Lanzhou Jiaotong University | Su Q.,Shandong Urban Construction Vocational College | Wu Y.,Lanzhou Jiaotong University
Advanced Materials Research | Year: 2011

In this paper, the differential equations of box beams are established based on the principle of minimum potential energy and the variational method. The elastic stiffness matrix and geometric stiffness matrix considering shear lag and compression-flexure effects are induced in this paper. And a finite element program is developed. Then the influence of compression-flexure effects to shear lag effect of box beam is analyzed. Source

Zhang B.,Shandong University | Li S.-C.,Shandong University | Yang X.-Y.,Shandong Urban Construction Vocational College | Wang B.,China Construction Fifth Engineering Division Corporation | Li M.-T.,Shandong Jiaotong University
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

The uniaxial compression mechanical properties and anchoring effect of jointed rock mass with different crack fillings were analyzed. The influences of different crack fillings on jointed rock mass mechanical properties and anchoring effect were studied through similar material pieces uniaxial compression testing and numerical computation. The research results show that in a certain extent the compressive strength peak values increase with the increment of crack fillings elastic modulus; the less the differences between crack filling elastic modulus and that of matrix material, the better the jointed rock mass post-peak plasticity properties; there are little influences affected by crack fillings on bolted jointed rock mass post-peak plasticity properties; the more the differences between crack filling elastic modulus and that of matrix material, the more rapidly the stresses decrease after peak; the tensile stress begins to appear along the loading direction when the elastic modulus of crack filling is less than that of matrix material, the tensile stress peak values and distribution areas increase with the decrease of crack filling elastic modulus. Source

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