物联网在文化遗产保护领域应用的关键——测控技术

各种类型的传感器是探测和获取外界信息的重要手段,是物联网的重要感知器件,因此测控技术成为物联网的核心基础技术。本研究首先介绍了测控技术与物联网的基本概念和关系;然后通过分析测控技术对文化遗产保护的重要性和文化遗产保护与发展面临着的巨大挑战,提出基于物联网的文化遗产保护的多项关键测控技术;最后结合测控技术在文化遗产保护的典型应用,给出了关于文化遗产保护领域物联网建设的若干建议。     

Evaluation of Side Boundary Effects on Dynamic Numerical Modeling for Centrifugal Model Tests

Four different boundary conditions consisting of fixed nodes, motion of roller only in the z or the x direction, and equivalent motion of two side boundaries were applied with a finite element code to simulate seismic behavior of two foundation conditions consisting of dry loose and dense sands. Comparing numerical results with physical model tests indicates that data obtained from the finite element code when considering soil nonlinearity with a sand model based on the tij concept have acceptable agreements with those from dynamic centrifuge tests regardless of the boundary conditions. The results from the boundary conditions of roller in the x direction and equivalent motion of two side boundaries agree well with the experimental data in wave peaks. The two side boundary conditions also keep the ground middle undisturbed and provide the results that are similar to those obtained from the wave amplification experimental data. For numerical simulations of centrifuge model tests, the side boundary condition with roller in the x direction is recommended because of low computation time and high simulation quality.