Numerical Simulation of Fluid Structure Interaction between Flow and Steel Pipe Pile Platform in Deep Water

In this paper, the two-way coupling of flow and steel pipe pile platform is simulated by ANSYS Workbench. Taking the construction platform in the deep water area of the Yangtze River Estuary as an example, the stress and deformation characteristics of the steel pipe pile platform under current force are analyzed in detail. As a result, it is suggested the platform piles should be arranged regularly and the connected node de-sign of the platform structure should be strengthened to ensure the safety.

THE COMPACTION OF TIME-DEPENDENT VISCOUS GRANULAR MATERIALS CONSIDERING INERTIAL FORCES

In the present paper, compactions of time-dependent viscous granular materials are simulated step by step using the automatic adaptive mesh generation schemes. Inertial forces of the viscous incompressible aggregates are taken into account. The corresponding conservation equations, the weighted-integral formulations, and penalty finite element model are investigated. The fully discrete finite element equations for the simulation are derived. Polygonal particles of aggregates are simplified as mixed three-node and four-node elements. The automatic adaptive mesh generation schemes include contact detection algorithms, and mesh upgrade schemes. Solutions of the numerical simulation are in good agreement with some results from literatures. With minor modification, the proposed numerical model can be applied in several industries, including the pharmaceutical, ceramic, food, and household product manufacturing.

Finite element analysis of creep for plane steel frames in fire

Steel is widely used for the construction of bridges,buildings,towers,and other structures because of its great strength,light weight,ductility,and ease of fabrication,but the cost of fireproofing is a major disadvantage.Therefore,the resistance of a steel structure to fire is a significant subject for modern society.In the past,for simplification,creep behavior was not taken into account in research on the resistance of a steel structure to fire.However,it was demonstrated that the effect of creep is considerable at temperatures that commonly reach 600℃and should not be neglected in this context.In this paper,a co-rotational total Lagrangian finite element formulation is derived,and the corresponding numerical model is developed to study the creep behavior of plane steel frames in fire conditions.The geometric nonlinearity,material nonlinearity,high temperature creep,and temperature rate of change are taken into account.To verify the accuracy and efficiency of the numerical model,four prototypical numerical examples are analyzed using this model,and the results show very good agreement with the solutions in the literature.Next,the numerical model is used to analyze the creep behavior of the plane steel frames under decreasing temperatures.The results indicate that the effect of creep is negligible at temperatures lower than 500℃and is considerable at temperatures higher than 500℃.In addition,the heating rate is a critical factor in the failure point of the steel frames.Furthermore,it is demonstrated that the deflection at the midpoint of the steel beam,considering creep behavior,is approximately 13%larger than for the situation in which creep is ignored.At temperatures higher than 500℃,the deformed steel member may recover approximately 20%of the total deflection.The application of the numerical model proposed in this paper is greatly beneficial to the steel industry for creep analysis,and the numerical results make a significant contribution to the understanding of resistance and protection for steel structures against disastrous fires.

Implementation of total Lagrangian formulation for the elasto-plastic analysis of plane steel frames exposed to fire

In this paper,the co-rotational total Lagrangian forms of finite element formulations are derived to perform elasto-plastic analysis for plane steel frames that either experience increasing external loading at ambient temperature or constant external loading at elevated temperatures.Geometric nonlinearities and thermal-expansion effects are considered.A series of programs were developed based on these formulations.To verify the accuracy and efficiency of the nonlinear finite element programs,numerical benchmark tests were performed,and the results from these tests are in a good agreement with the literature.The effects of the nonlinear terms of the stiffness matrices on the computational results were investigated in detail.It was also demonstrated that the influence of geometric nonlinearities on the incremental steps of the finite element analysis for plane steel frames in the presence of fire is limited.

The quality traceability system for prefabricated buildings using blockchain:An integrated framework

The quality traceability of precast components has largely affected the widespread adoption of prefabricated buildings.Blockchain technology provides an effective solution to change the centralized storage mode of traditional traceability system and its related disadvantages.In this paper,we propose a framework of quality traceability system for precast components based on blockchain technology.The system framework adopts a hybrid blockchain architecture and dual storage mode,defines three types of smart contracts,and creates an interactive and efficient source tracing query method,which could effectively achieve the goals of decentralization,openness,and non-tamperability,as well as efficient traceability.