The single-layer latticed cylindrical shell is one of the most widely adopted space-fl'amed structures.In this paper,free vibration properties and dynamic response to horizontal and vertical seismic waves of singl...The single-layer latticed cylindrical shell is one of the most widely adopted space-fl'amed structures.In this paper,free vibration properties and dynamic response to horizontal and vertical seismic waves of single-layer latticed cylindrical shells are analyzed by the finite element method using ANSYS software.In the numerical study,where hundreds of cases were analyzed,the parameters considered included rise-span ratio,length-span ratio,surface load and member section size.Moreover,to better define the actual behavior of single-layer latticed shells,the study is focused on the dynamic stress response to both axial forces and bending moments.Based on the numerical results,the effects of the parameters considered on the stresses are discussed and a modified seismic force coefficient method is suggested.In addition,some advice based on these research results is presented to help in the future design of such structures.展开更多
为解决污水源热泵中换热器防堵和防垢的问题,提出了带引射回流功能的污水旋流防阻机,并进行了砂水和生活污水分离试验。结果表明:该防阻机对砂子(75~250μm)和污杂物(<4 mm)均有较好的分离效果,分离效率分别为98.17%~100%和94.33%~96...为解决污水源热泵中换热器防堵和防垢的问题,提出了带引射回流功能的污水旋流防阻机,并进行了砂水和生活污水分离试验。结果表明:该防阻机对砂子(75~250μm)和污杂物(<4 mm)均有较好的分离效果,分离效率分别为98.17%~100%和94.33%~96.96%。优化的溢流管与圆柱段长度比值的范围大小与离散相密度成正比。并且,引射回流装置的存在不仅实现了防堵和连续排污,还显著减轻了"溢流跑粗"的影响,提高了分离效率。防阻机的能耗基本不随溢流管与圆柱段长度比值的变化而变化,且总的能量损失较小(小于17 k Pa)。在保证较高分离效率的同时,分流比可以控制在较低的水平(小于10%),相比传统污水源热泵中的污水防阻机,可利用污水量大大提高。展开更多
基金National Natural Science Foundation of China,Grant No.59895410
文摘The single-layer latticed cylindrical shell is one of the most widely adopted space-fl'amed structures.In this paper,free vibration properties and dynamic response to horizontal and vertical seismic waves of single-layer latticed cylindrical shells are analyzed by the finite element method using ANSYS software.In the numerical study,where hundreds of cases were analyzed,the parameters considered included rise-span ratio,length-span ratio,surface load and member section size.Moreover,to better define the actual behavior of single-layer latticed shells,the study is focused on the dynamic stress response to both axial forces and bending moments.Based on the numerical results,the effects of the parameters considered on the stresses are discussed and a modified seismic force coefficient method is suggested.In addition,some advice based on these research results is presented to help in the future design of such structures.
文摘为解决污水源热泵中换热器防堵和防垢的问题,提出了带引射回流功能的污水旋流防阻机,并进行了砂水和生活污水分离试验。结果表明:该防阻机对砂子(75~250μm)和污杂物(<4 mm)均有较好的分离效果,分离效率分别为98.17%~100%和94.33%~96.96%。优化的溢流管与圆柱段长度比值的范围大小与离散相密度成正比。并且,引射回流装置的存在不仅实现了防堵和连续排污,还显著减轻了"溢流跑粗"的影响,提高了分离效率。防阻机的能耗基本不随溢流管与圆柱段长度比值的变化而变化,且总的能量损失较小(小于17 k Pa)。在保证较高分离效率的同时,分流比可以控制在较低的水平(小于10%),相比传统污水源热泵中的污水防阻机,可利用污水量大大提高。
