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易谷丰 《数字海洋与水下攻防》2019,2(3):64-69
电磁扫雷具是主要的非接触扫雷具之一,用于扫除带有磁引信的非触发水雷。为了诱动水雷磁引信,电磁扫雷具产生的磁场必须与水雷磁引信的动作要求相适应。基于实际的工程模型,应用 Ansoft Maxwell 对电极阵电磁扫雷具的磁场分布进行分析,绘制磁感应强度分布图和通过特性曲线,以便对产品进行设计验证和优化设计。同样的方法还可拓展用于其它电磁扫雷具的设计,以提升设计效率和水平。 相似文献
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针对我国北方浅海地区风电工程多桩承台所耐受环境,通过模拟海洋工况,如冻融循环、氯盐溶液浸泡,并在此模拟环境作用基础上进行抗压强度试验和抗折强度试验,再结合钢筋粘结的拔出试验,探讨不同混凝土强度等级在氯盐侵蚀的情况下,分别进行不同次数的冻融循环,来对比分析各种工况对混凝土物理性能的影响。运用超声波探测技术有效地解释混凝土在冻融循环和氯离子复合作用下强度降低的劣化机理。最后,利用有限元数值模拟多桩承台的作业环境,再一次验证了冻融循环对风机承台混凝土结构的影响规律。此研究可为北方海域冻融环境较为恶劣区域的风电项目建设提供有益参考。 相似文献
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庞广智 《数字海洋与水下攻防》2022,5(6):572-579
以陆地枪械发射内弹道方程组理论为基础,结合水下聚能剪切器动作的技术特点,对动刀运动的能量转化机理和刀架内部组件的动力学响应进行了综合分析,建立归一化数学模型,用于内弹道参量变化特性曲线的数值计算。通过对某型号水下剪切器内弹道仿真求解,定量分析了各参量变化过程,论证了短行程聚能剪切方案的可行性,为后继内弹道设计及装药参量的优化奠定了理论基础。 相似文献
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All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static or dynamic calculation methods. In this paper, the finite element method (FEM) and theoretical analysis method are combined to analyze the structural property, bearing behavior and failure mode of the all-vertical-piled wharf in offshore deep water, and to establish simplified calculation methods determining the horizontal static ultimate bearing capacity and the dynamic response for the all-vertical-piled wharf. Firstly, the bearing capability and failure mechanism for all-vertical-piled wharf are studied by use of FEM, and the failure criterion is put forward for all-vertical-piled wharf based on the ‘plastic hinge’. According to the failure criterion and P-Y curve method, the simplified calculation method of the horizontal static ultimate bearing capacity for all-vertical-piled wharf is proposed, and it is verified that the simplified method is reasonable by comparison with the FEM. Secondly, the displacement dynamic magnification factor for the all-vertical-piled wharf under wave cyclic loads and ship impact loads is calculated by the FEM and the theory formula based on the single degree of freedom (SDOF) system. The results obtained by the two methods are in good agreement with each other, and the simplified calculation method of the displacement dynamic magnification factor for all-vertical-piled wharf under dynamic loads is proposed. Then the simplified calculation method determining the dynamic response for the all-vertical-piled wharf is proposed in combination with P-Y curve method. That is, the dynamic response of the structure can be obtained through the static calculation results of P-Y curve method multiplied by the displacement dynamic magnification factor. The feasibility of the simplified dynamic response method is verified by comparison with the FEM under different conditions. 相似文献
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There has been a growing trend in the development of offshore deep-water ports in China. For such deep sea projects, all-vertical-piled wharves are suitable structures and generally located in open waters, greatly affected by wave action. Currently, no systematic studies or simplified numerical methods are available for deriving the dynamic characteristics and dynamic responses of all-vertical-piled wharves under wave cyclic loads. In this article, we compare the dynamic characteristics of an all-vertical-piled wharf with those of a traditional inshore high-piled wharf through numerical analysis; our research reveals that the vibration period of an all-vertical-piled wharf under cyclic loading is longer than that of an inshore high-piled wharf and is much closer to the period of the loading wave. Therefore, dynamic calculation and analysis should be conducted when designing and calculating the characteristics of an all-vertical-piled wharf. We establish a dynamic finite element model to examine the dynamic response of an all-vertical-piled wharf under wave cyclic loads and compare the results with those under wave equivalent static load; the comparison indicates that dynamic amplification of the structure is evident when the wave dynamic load effect is taken into account. Furthermore, a simplified dynamic numerical method for calculating the dynamic response of an all-vertical-piled wharf is established based on the P-Y curve. Compared with finite element analysis, the simplified method is more convenient to use and applicable to large structural deformation while considering the soil non-linearity. We confirmed that the simplified method has acceptable accuracy and can be used in engineering applications. 相似文献
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我国码头新结构型式综述 总被引:1,自引:0,他引:1
对我国近些年出现的几种新型码头结构进行了分析和综述。导管架码头结构型式是一种新型的结构型式,结构的整体刚度大、水平变位小、透空性好、波浪反射小,在开敞式环境下可适当降低码头面高程;椭圆沉箱墩式结构解决前后不均匀沉降的问题,提高了结构的整体稳定性;内河架空直立墩式结构对大水位差适应能力强,结构紧凑,对水流穿行影响小,装卸作业时泊稳条件好,是内河航道未来的发展方向。 相似文献
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大洋铁锰结壳是继大洋多金属结核之后出现的又一极具潜在经济价值的水下固体矿产(王毅民,1992),富含Mn、Fe、Cu、Co、Ni和Pt多种金属元素及非金属元素P,Co含量最高可达2.5%,是大陆含Co矿床的数倍到数十倍,铂的平均含量也是上地壳的80倍。据众多科学家的初步估计,仅太平洋西部火山构造隆起带上,铁锰结壳矿床的潜在资源量就达10亿t,其中Co金属含量可达600万~700万t,经济总价值超过1000亿美元(Klinkhammer et al.,1980;Halbach et al.,1984;DeCarlo et al.,1987;何高文等,2001)。这与全球陆地已探明Co资源总量仅为1 500万t相比,数量极为可观,并且结壳的产出水深多小于3000 m, 易于进行系统的、大量的样品采集,开采风险及开采时对环境的影响也较小。因此,近年来,随着世界经济的蓬勃发展和高新技术的开发, 对Mn、Cu、Co、Ni等元素的需求日益增大及由此所导致的陆地上这些资源的迅速枯竭,使人们纷纷将目光转向深海底矿产,加大了对海底铁锰结壳资源的研究力度和深度,其资源的经济地位也相应进一步提高。据专家预测,大洋铁锰结壳很可能会比大洋的金属结核率先实现商业性开采,并成为21世纪新兴的海洋矿产产业(Hein et al.,1998;潘家华等,1995)。
此外,结壳还有净化空气中SO2与NO2的氧化催化剂等用途,并且铁锰结壳成矿环境的研究,还具有较高的科学价值,可使科学家进一步深入了解和认识地内深部物源、海底水-岩反应、金属成矿富集过程及其中的微生物成矿作用乃至古海洋环境演变等问题,而这些问题迄今仍未得到完善解决,是当前地学和海洋学领域的研究热点。这就使铁锰结壳成矿环境的研究显得尤为重要。 相似文献