Research on the Multidimensional Constraint Stability of Bridge Structure Modeling Based on Optimization Model

Transcription

1 th International Conference on Advances in Social Science, Humanities, and Management (ASSHM 2016) ISBN: Research on the Multidimensional Constraint Stability of Bridge Structure Modeling Based on Optimization Model Cheng Kang 1 Abstract In this paper, we conduct research on the multidimensional constraint stability of bridge structure modeling based on the optimization model. The current internal and the external research results to the truss web structure, the high internode the aspect ratio and the stiffness of the middle truss brace of the truss web, deflection of composite beams of the impact of stress is a very important problem in the design of the bridge. Structural health monitoring is the use of the field of the non-destructive sensing technology, including the structural response, including structural system characteristics analysis, to achieve the purpose of monitoring structural damage or degradation. Under this basis, this paper proposes the new idea on the modelling and simulates the performance. Keywords: Multidimensional, Constraint Stability, Bridge Structure, Optimization Model. Introduction The optimization design is the new discipline of the 1960s developing, and it devoted to studying the improved structure design method of highly efficiency, with the aim of designing not only economy and reliable structure. The optimization design causes the structure with every effort rational design, in objective function of some definition that requests in full satisfiedly stipulated certain functions. Bridge structure defects assessment became the various countries traffic control department universal matter of concern. Structural health monitoring is the use of the field of the non-destructive sensing technology, including the structural response, including structural system characteristics analysis, to achieve the purpose of monitoring structural damage or degradation. Large-scale bridge structural health monitoring system and traditional test method of the difference between real time, automation, integration and the network system, health monitoring system, including sensor subsystem, the data acquisition and transmission subsystem, data analysis and processing subsystem, data management subsystem. The systematic architecture can be then summarized as the follows. Data analysis and processing system. The data analysis and treatment system including the damage recognition, the model correction, the defects assessment, the reliability forecast and safety pre-warning subsystem that comprised of the damage recognition software and model correction software and structure safety assessment software. Bridge damage identification and the model modification, and the results of the safety assessment will be stored as bridge history archives in the data management subsystem. Sensor subsystem. The sensory subsystem is a hardware system, which is used for sensing the load and effect information of the bridge structure, and is outputted in the 1 Sichuan College of Architectural Technology, Deyang, Sichuan, China 276

2 form of electric, optical, acoustic and the thermal physical quantities. The subsystem is the most advanced and basic subsystem of the health monitoring system. Data management subsystem. Data management subsystem is the core of the database system, database management bridge construction information, geometric information, monitoring information and analysis of the results of all data. Besides the management system, the CAD assisted technique is also essential. CAD is a highly technical, practical course. Through modelling to enable us to more systematic understanding of the basic concepts of AutoCAD and basic theory, master their basic commands, basic methods, drawing skills, according to the specific needs of the skilled proficiency in drawing two-dimensional plan and three-dimensional map to achieve the comprehensive use of the learned knowledge that methods to improve the design and the development capabilities of the purpose. In the later sections, we will integrate the technique and form our methodology. The Proposed Methodology Figure 1. The Sample Bridge Structure Modeling Demonstration. The Optimization Theory. In the recent decades, people tend to be based on probabilistic reliability optimization design showed the more intense interest in the design requirements of the system component failure probability is less than the allowable value, it can be said that the probability of the reliability theory in structural optimization design achieved successful application. At the same time, probabilistic reliability is extremely sensitive to parameters, and small parameter changes may lead to significant fluctuations in the final analysis results, which means that in the absence of sufficient data to accurately describe the random variables, the subjective assumptions largely lead to the results with the deepening of the research, probability reliability model is no longer the best choice. We consider the non-probabilistic reliability measurement as the follows. M R, S = R S (1) ( ) This linear form, given a different set of S and R, determines whether the state of the structure is safe or inactive. The uncertainty space is divided into two parts: the security domain and the failure domain while limit state plane as defined to be the follows. M R, S = R S = 0 (2) ( ) 277

3 Non probabilistic set reliability theory, some structure and function of hypersphere unit function relationship between the failure surfaces to determine the safety degree of the system, the definition of the non-probabilistic convex models of the reliability measure index and the value space in the failure domain and the basic variables of the unit hypersphere domain ratio is defined as failure of a system, simplified to 2D space is expressed as variables and failure area of unit circle area ratio as follows. i i ( ) α ( α ) min J x, y = M + 1 C (3) j j man i i i j LB j j UB x, x x, (4) i i i j LB j j UB y, y y, (5) Compared with the Newton method, the step size of the damping Newton method is more superior to the step value, so the convergence speed of the optimization problem is faster and the selection condition of the initial point is more relaxed, and it is obtained in the practical application with better effect. In the following formula 6~7, we define the corresponding features. u as fanmpw do M a ( R + E) R = Ch d m P( u) = n i= 0 n i= 0 h PN i i i, k h N i i, k ( u) ( u) The Structural Multidimensional Constraints. Solidworks is a widely used 3D CAD modeling and analysis software that automatically generates finite element meshes and calculates them after completing the design of basic parts, assemblies, and assemblies. If the results do not meet the design requirements, re-shape and calculate while until satisfied, so as to greatly improve the design level and efficiency. Start the Simulation plug-in for SolidWorks, create a new study, and mesh the pallet with a finite element mesh. Usually for large and complex shape of the model, the entity grid division as a unit type; the same time, in order to obtain good simulation analysis accuracy, should choose high-quality grid and grid automatic transition function is open, so that the network. When the lattice is divided, the area where the connection plate and the spacer are easy to produce great stress will form a larger mesh density, while the other parts will produce a relatively small mesh density. The core design and simulation of the architecture are shown in the figure two (6) (7) 278

4 Figure 2. The Structural Multidimensional Constraint Illustration. The Bridge Structure Modeling Pradigm. Aiming at the problem of data missing in the design of the new composite bridge structure, the finite element model of ANSYS was established to study the influence of the structural parameters such as the aspect ratio and the web stiffness on the overall performance of the bridge structure. The results show that with the increase of the height-width ratio or the stiffness of the webs, the maximum deflection nonlinearity of the new-type composite bridge structure decreases. When the aspect ratio is greater than 1 and less than 2, the maximum deflection of the beam is close to the zero. With the increase of the aspect ratio or the stiffness of the webs, the compressive stresses of the top plate and the bottom plate of the new composite bridge structure become smaller and the tensile stress of the bottom plate gradually increases. On the concrete slab in bridge truss web composite structure for the whole thickness of the beam height is very thin, while the middle truss has accounted for the majority of the composite beams, so the internode aspect ratio on the overall impact will be relatively large; in addition the middle truss brace stiffness very large, the distribution of strength and section size of each web member size also determines the force of bridge structure, so the middle truss stiffness also is the main factor affecting the truss web composite structure bridge force characteristics. The current internal and the external research results to the truss web structure, the high internode the aspect ratio and the stiffness of the middle truss brace of the truss web, deflection of composite beams of the impact of stress is a very important problem in the design of bridge. Considering this, we show the suggestions as follows. The new sensor is a research hotspot in the future. The use of the new sensor makes the original life of the bridge was given the self-inductance and self-diagnostic ability. The current direction of development includes light grating sensors, piezoelectric sensors, shape memory alloy sensors, etc. The optimization of sensor layout is the bridge structural health monitoring and diagnosis of an important issue, the current health monitoring system for high demand for the number of sensors, which can raise the cost for the construction of the bridge health monitoring system. At present, there is no unified, effective, universal, the damage quantification index for the evaluation of bridge structure health status, and it is difficult to reflect the damage of a local component to the whole bridge working condition. Therefore, it is an important approach to solve the practicality of bridge health monitoring system. 279

5 Conclusion Figure 3. The Bridge Structure Modeling Pradigm and the Flowchart. In this paper, we conduct research on the multidimensional constraint stability of the bridge structure modeling based on the optimization model. Bridge structure defects assessment became the various countries traffic control department universal matter of concern. Structural health monitoring is the use of the field of the non-destructive sensing technology, including the structural response, including structural system characteristics analysis, to achieve the purpose of monitoring structural damage or degradation. This paper systematically introduces the multidimensional constraint stability of the bridge structure modeling with the CAD and mathematical optimization model. In the later research, we will then apply the method on more related approaches to verify the effectiveness. References [1] Attary, N., Symans, M., Nagarajaiah, S., Reinhorn, A. M., Constantinou, M. C., Sarlis, A. A.,... & Taylor, D. (2015). Numerical simulations of a highway bridge structure employing passive negative stiffness device for seismic protection. Earthquake Engineering & Structural Dynamics, 44(6), [2] Qi, C., Ruijie, X., Shuqiu, W., Changbin, C., Haibin, M., Caihong, L.,... & Li, Z. (2015). Influence of annealing temperature on the lamellar and connecting bridge structure of stretched polypropylene microporous membrane. Polymer International, 64(3), [3] Wang, X., Zhen, C., Liu, X., Liu, X., Ma, L., Pan, C., & Hou, D. (2014). A new hole-bridge structure based on a SiO 2 nanoarray and its ferromagnetism. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 446, [4] Jung, W. Y., & Ju, B. S. (2016). Seismic Performance Evaluation of Bridge Structures Using 3D Finite Element Methods in South Korea. World Academy of Science, Engineering and Technology, International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering,10(3), [5] Dai, Z., Wang, S., & Yan, Z. (2012, June). BSHM-WSN: A wireless sensor network for bridge structure health monitoring. In Modelling, Identification & Control (ICMIC), 2012 Proceedings of International Conference on (pp ). IEEE. 280

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