接头是沉管隧道中最薄弱的一环,在受到地震和不均匀沉降等作用下,接头会发生横向变形,并通过接头中的剪力键传递。目前,国内外沉管隧道管节接头变形规律的研究较少集中在剪力键上,更缺少管节接头整体力学性能试验数据的支持。根据沉管...接头是沉管隧道中最薄弱的一环,在受到地震和不均匀沉降等作用下,接头会发生横向变形,并通过接头中的剪力键传递。目前,国内外沉管隧道管节接头变形规律的研究较少集中在剪力键上,更缺少管节接头整体力学性能试验数据的支持。根据沉管隧道接头构造设计特点,该文提出了一套测试接头压剪承载力和破坏模式的破坏试验方法和加载方案,并开展了几何比尺为1∶10的管节接头压剪试验,研究接头在低周往复剪切荷载下的力学性能,记录其荷载-位移曲线,最终获得接头压剪刚度曲线。试验结果表明,管节接头和单个剪力键的承载力分别是310 k N/355 k N(正/负向)和88 k N,均比设计承载力高。而接头剪力键的破坏模式主要表现为局部翘曲破坏和凸榫根部拉裂破坏。展开更多
This study reports a hybrid method which allows the formation of biocomposites on stainless steel implants. The main idea of the method is to create multilayer coatings consisting of titanium primer layer and a microa...This study reports a hybrid method which allows the formation of biocomposites on stainless steel implants. The main idea of the method is to create multilayer coatings consisting of titanium primer layer and a microarc calcium-phosphate coating. The titanium layer is deposited from plasma of continuous vacuum-arc discharge, and calcium-phosphate coating is formed by the microarc oxidation technique. The purpose of the hybrid method is to combine the properties of good strength stainless steel with high bioactivity of calcium-phosphate coating. This paper describes the chemical composition, morphology characteristics, adhesion and the ability of the formed biocomposites to stimulate the processes of osteoinduction. It is expedient to use such biocomposites for implants which carry heavy loads and are intended for long-term use, e.g. total knee endoprosthesis.展开更多
文摘接头是沉管隧道中最薄弱的一环,在受到地震和不均匀沉降等作用下,接头会发生横向变形,并通过接头中的剪力键传递。目前,国内外沉管隧道管节接头变形规律的研究较少集中在剪力键上,更缺少管节接头整体力学性能试验数据的支持。根据沉管隧道接头构造设计特点,该文提出了一套测试接头压剪承载力和破坏模式的破坏试验方法和加载方案,并开展了几何比尺为1∶10的管节接头压剪试验,研究接头在低周往复剪切荷载下的力学性能,记录其荷载-位移曲线,最终获得接头压剪刚度曲线。试验结果表明,管节接头和单个剪力键的承载力分别是310 k N/355 k N(正/负向)和88 k N,均比设计承载力高。而接头剪力键的破坏模式主要表现为局部翘曲破坏和凸榫根部拉裂破坏。
文摘This study reports a hybrid method which allows the formation of biocomposites on stainless steel implants. The main idea of the method is to create multilayer coatings consisting of titanium primer layer and a microarc calcium-phosphate coating. The titanium layer is deposited from plasma of continuous vacuum-arc discharge, and calcium-phosphate coating is formed by the microarc oxidation technique. The purpose of the hybrid method is to combine the properties of good strength stainless steel with high bioactivity of calcium-phosphate coating. This paper describes the chemical composition, morphology characteristics, adhesion and the ability of the formed biocomposites to stimulate the processes of osteoinduction. It is expedient to use such biocomposites for implants which carry heavy loads and are intended for long-term use, e.g. total knee endoprosthesis.
