Deep-sea cobalt crusts water jet cutting method is proposed to avoid cutter impact load. With simulation calculations and experimental tests, water jet system parameters and its cutting ability were studied. Simula-ti...Deep-sea cobalt crusts water jet cutting method is proposed to avoid cutter impact load. With simulation calculations and experimental tests, water jet system parameters and its cutting ability were studied. Simula-tion results show that working pressure, ejection range and ejection angle of water jet system are main parameters of its cutting ability. Its important degree is in turn the working pressure, ejection range and ejection angle. Increasing water jet system working pressure is the most effective way to improve its cutting ability. When water jet working pressure is constant, in order to improve its cutting ability, the ejection range should be less than 4mm (four times of nozzle diameter) and the ejection angle should be about 13o. Experimental results show that there is a threshold pressure during water jet cutting cobalt crusts simulation material. With the increase of water jet working pressure, its cutting ability increases dramatically. With the increasing of water jet ejection range, its cutting ability decreases sharply. The optimal ejection angle is about 13o</sup.展开更多
1 Introduction It is known that more than 300 lakes and lagoons are present in the Crimean Peninsula,which are divided depending on position to 7 groups:Perekop,Tarkhankut,Evpatoriyskaya,Khersonesskaya,lake on the mou...1 Introduction It is known that more than 300 lakes and lagoons are present in the Crimean Peninsula,which are divided depending on position to 7 groups:Perekop,Tarkhankut,Evpatoriyskaya,Khersonesskaya,lake on the mountainpastures,Kerch and Genicheskaya.Almost the all lakes,with the exception of the small freshwater lakes,which situated on mountain pastures of the Main ridge of展开更多
海底表层的结构物在使用中可能受到动荷载作用,为保证其的长期稳定性,有必要对海床表层的深海超软土动力学特性展开研究。使用Anton Paar MCR302流变仪,采用应变控制模式,对含水率高于液限的深海超软土进行动态剪切测试,研究动态流变参...海底表层的结构物在使用中可能受到动荷载作用,为保证其的长期稳定性,有必要对海床表层的深海超软土动力学特性展开研究。使用Anton Paar MCR302流变仪,采用应变控制模式,对含水率高于液限的深海超软土进行动态剪切测试,研究动态流变参数、动剪切模量G和阻尼比λ的变化规律。结果表明,随着剪切应变的增大,深海超软土的变形由可恢复的弹性变形主导逐渐过渡为不可恢复的黏性变形主导。通过建立动态流变参数与动剪切模量G和阻尼比λ的关系,探讨了深海超软土的动力特性。根据深海超软土动剪切模量G的变化特征,提出了峰值参考应变的概念,建立了最大动剪模量G_(max)与归一化含水率w/w_(p)(w为含水率,w_(p)为塑性含水率)的关系。结果还显示,相较于常规黏土,深海超软土的G/G_(max-γ)(γ为剪切应变)曲线衰减较快,且受塑性指数影响较小。深海超软土的阻尼比整体偏高,并随剪切应变的增大快速上升。根据试验结果,给出描述深海超软土G/G_(max-γ)、λ-γ曲线的数学模型。展开更多
文摘Deep-sea cobalt crusts water jet cutting method is proposed to avoid cutter impact load. With simulation calculations and experimental tests, water jet system parameters and its cutting ability were studied. Simula-tion results show that working pressure, ejection range and ejection angle of water jet system are main parameters of its cutting ability. Its important degree is in turn the working pressure, ejection range and ejection angle. Increasing water jet system working pressure is the most effective way to improve its cutting ability. When water jet working pressure is constant, in order to improve its cutting ability, the ejection range should be less than 4mm (four times of nozzle diameter) and the ejection angle should be about 13o. Experimental results show that there is a threshold pressure during water jet cutting cobalt crusts simulation material. With the increase of water jet working pressure, its cutting ability increases dramatically. With the increasing of water jet ejection range, its cutting ability decreases sharply. The optimal ejection angle is about 13o</sup.
文摘1 Introduction It is known that more than 300 lakes and lagoons are present in the Crimean Peninsula,which are divided depending on position to 7 groups:Perekop,Tarkhankut,Evpatoriyskaya,Khersonesskaya,lake on the mountainpastures,Kerch and Genicheskaya.Almost the all lakes,with the exception of the small freshwater lakes,which situated on mountain pastures of the Main ridge of
文摘海底表层的结构物在使用中可能受到动荷载作用,为保证其的长期稳定性,有必要对海床表层的深海超软土动力学特性展开研究。使用Anton Paar MCR302流变仪,采用应变控制模式,对含水率高于液限的深海超软土进行动态剪切测试,研究动态流变参数、动剪切模量G和阻尼比λ的变化规律。结果表明,随着剪切应变的增大,深海超软土的变形由可恢复的弹性变形主导逐渐过渡为不可恢复的黏性变形主导。通过建立动态流变参数与动剪切模量G和阻尼比λ的关系,探讨了深海超软土的动力特性。根据深海超软土动剪切模量G的变化特征,提出了峰值参考应变的概念,建立了最大动剪模量G_(max)与归一化含水率w/w_(p)(w为含水率,w_(p)为塑性含水率)的关系。结果还显示,相较于常规黏土,深海超软土的G/G_(max-γ)(γ为剪切应变)曲线衰减较快,且受塑性指数影响较小。深海超软土的阻尼比整体偏高,并随剪切应变的增大快速上升。根据试验结果,给出描述深海超软土G/G_(max-γ)、λ-γ曲线的数学模型。
