在倒装芯片的单粒子效应防护设计验证中,重离子在到达器件敏感区前要经过几百微米的衬底材料,需要计算器件敏感区中离子的线性能量传输(LET)值。采用兰州重离子加速器加速的55 Me V/μ58Ni离子对基于倒装的Xilinx公司550万门现场可编程...在倒装芯片的单粒子效应防护设计验证中,重离子在到达器件敏感区前要经过几百微米的衬底材料,需要计算器件敏感区中离子的线性能量传输(LET)值。采用兰州重离子加速器加速的55 Me V/μ58Ni离子对基于倒装的Xilinx公司550万门现场可编程门阵列(FPGA)实现的典型系统的单粒子效应防护设计进行了试验验证,采用SRIM、FLUKA和GEANT等不同方法对试验中的LET值进行了分析,同时将SRIM分析的典型结果与基于磁偏转飞行时间法的试验数据进行了比较,发现与现有的重离子分析结果有一定差异。因此在防护验证中采用离子LET作为主要参数的情况下,应对重离子(尤其是高能段)的LET的计算方法进行约定,以规范试验过程,增强数据的可比性。展开更多
Temperature is a significant load on bridges,particularly for long-span steel box girder bridges.This study investigates the temperature-induced static responses of a long-span suspension bridge under real service env...Temperature is a significant load on bridges,particularly for long-span steel box girder bridges.This study investigates the temperature-induced static responses of a long-span suspension bridge under real service environmental conditions using numerical simulations and field measurements.Detailed 2 D finite element(FE)models of a typical section for the box girder,main cable,hanger,tower column,and crossbeam are constructed.The thermal boundary conditions are determined strictly according to the surrounding environments of a typical sunny day and applied to the FE models.A transient heat-transfer analysis is performed and the time-dependent temperature and its distribution on the bridge are obtained.In addition,a fine,3 D FE model of the bridge is developed for a structural analysis.The calculated temperatures are applied to the 3 D model and the temperature-induced structural responses are simulated.The simulated temperatures and the associated static responses have good agreement with the measured counterparts and support the numerical simulation method.The main cable and bridge deck make the greatest contributions to the temperature effects on the suspension bridge.The static responses of bridge caused by the design vehicle load are also calculated.The daily variation of the temperature-induced static responses is comparable with,even higher than,that of the design vehicle load.展开更多
文摘在倒装芯片的单粒子效应防护设计验证中,重离子在到达器件敏感区前要经过几百微米的衬底材料,需要计算器件敏感区中离子的线性能量传输(LET)值。采用兰州重离子加速器加速的55 Me V/μ58Ni离子对基于倒装的Xilinx公司550万门现场可编程门阵列(FPGA)实现的典型系统的单粒子效应防护设计进行了试验验证,采用SRIM、FLUKA和GEANT等不同方法对试验中的LET值进行了分析,同时将SRIM分析的典型结果与基于磁偏转飞行时间法的试验数据进行了比较,发现与现有的重离子分析结果有一定差异。因此在防护验证中采用离子LET作为主要参数的情况下,应对重离子(尤其是高能段)的LET的计算方法进行约定,以规范试验过程,增强数据的可比性。
基金supported by the National Key Research and Development Program of China(No.2017YFC0803300)the Science and Technology Planning Project of Guangdong Province(No.2014A020218003),China。
文摘Temperature is a significant load on bridges,particularly for long-span steel box girder bridges.This study investigates the temperature-induced static responses of a long-span suspension bridge under real service environmental conditions using numerical simulations and field measurements.Detailed 2 D finite element(FE)models of a typical section for the box girder,main cable,hanger,tower column,and crossbeam are constructed.The thermal boundary conditions are determined strictly according to the surrounding environments of a typical sunny day and applied to the FE models.A transient heat-transfer analysis is performed and the time-dependent temperature and its distribution on the bridge are obtained.In addition,a fine,3 D FE model of the bridge is developed for a structural analysis.The calculated temperatures are applied to the 3 D model and the temperature-induced structural responses are simulated.The simulated temperatures and the associated static responses have good agreement with the measured counterparts and support the numerical simulation method.The main cable and bridge deck make the greatest contributions to the temperature effects on the suspension bridge.The static responses of bridge caused by the design vehicle load are also calculated.The daily variation of the temperature-induced static responses is comparable with,even higher than,that of the design vehicle load.
