The objective of this work was to investigate the effect of stiffener strength on the failure mode of an outer-stiffened plate subjected to confined blast loading. A relatively rigid box with one open side was designed, to provide a confined space, and the stiffened plate was fixed onto the open side. Various field blast experiments of stiffened plates with different dimensions were conducted. Transducers were placed on typical points to record the overpressure history. The post-explosion deformation was drawn utilizing the 3D scanner technique, and the failure modes of the stiffened plates were examined in detail. The effect of plate thickness, stiffener thickness, stiffener height, and stand-off distance on the failure mode of the stiffened plate is discussed. It was shown that two typical failure modes were observed in the stiffened plates, namely uniform global dome deformation and nonuniform dome deformation, with local lattice along the stiffeners. The transformation of these two deformation modes originated from the relative strength of the stiffener compared to the plate, hence a relative strength factor was proposed to clarify the division.

Abstract The authors made a decision to withdraw the paper.

船舶推进轴系引起的船体振动问题日益突出,为了减小推进轴系传递给船体的振动,从改变振动传递路径的角度提出一种轴系整体弹性支撑方案.建立有限元模型,改变支撑平台结构刚性和隔振器刚度分别计算轴承基座间相对位移和轴承载荷.所选取的平台方案中,在重力下轴承基座间最大相对位移为1.216 mm.推力作用下当推力大于500 kN时,采用1阶弯曲频率在18.2 Hz及以上的平台方案时,轴承基座间最大相对位移小于0.3 mm,隔振器刚度变化则对轴承载荷影响不大.通过调整平台刚度和隔振器刚度,可以将弹性支撑系统对轴系影响控制在标准范围内,保证轴系安全运行.

[Objectives] The Integrated Vibration Isolation System (IVIS) for marine thrust bearings can be used to change the longitudinal vibration transmission path of the propulsion shafting system and attenuate the vibration energy transmitted from the propeller to the hull,thereby achieving the purpose of noise reduction.[Methods] In order to obtain the transmission rules of the propeller excitation in different directions,a numerical analysis model of the propeller-shaft-hull was established. Then,the vibration transmission characteristics of the IVIS under the propeller's unit excitation forces in the longitudinal and lateral directions were analyzed. Under these two installation methods of thrust bearings,i.e. by means of the IVIS and the traditional rigid support,the vibration responses of the hull were compared and the corresponding dominant modes were identified. In addition, the longitudinal force spectrum of the propeller was calculated by indirect identification method,and the vibration isolation performance of the IVIS was evaluated by using it as an input. Finally,the experimental study on the response characteristics resulting from the propeller excitation of the IVIS was carried out.[Results] The results show that, compared with the traditional rigid support method,the IVIS has no obvious vibration isolation effect for the propeller's lateral excitation force,but has a vibration isolation effect of more than 10 dB for the longitudinal excitation.[Conclusions] The application of the IVIS can generate satisfactory vibration isolation effect of the marine thrust bearings in longitudinal direction,and this result can provide a new method for the design of marine thrust bearing vibration isolation devices。

永磁轴承悬浮时的受力,与磁轴承的结构及永磁体材料参数有关.为了解决永磁轴承在大承载力工况时的应用,本文在已有的简单永磁轴承结构基础上,结合永磁体工作特性,针对一种新的径向磁化永磁推力轴承,使用虚位移法及线性叠加原理,得出了新型永磁推力轴承的数学解析模型.模型表明,在小间隙工况下,轴向承载力随气隙的增大而减小;间隙固定时,轴向承载力随轴向位移增加先增大后减小,存在最大承载力.利用有限元法对轴向磁力进行仿真计算,仿真结果与解析结果基本吻合.

[Objectives] The transmission path of the longitudinal vibration of propeller shafting can be changed and the base response attenuated via a Resonance Changer(RC)integrated in the thrust bearing, enabling the natural frequency of the shafting to be avoided by the propeller's blade frequency and multiplier frequency excitation force. In this way,the purposes of vibration reduction and frequency adjustment can be achieved.[Methods] In this paper,the mechanical model of longitudinal vibration of propeller shafting is established and the vibration model of the propeller shaft system is calculated on the basis of the transfer matrix method. The influence of the main parameters of the RC on the vibration isolation effect of propeller shafting is analyzed by taking the force transmission rate as the index. The methods of the minimization of maximum value and parameter correction of the curve area are used to optimize the main parameters of the RC.[Results] The results show that the vibration isolation effect of propeller shafting is significantly improved when the RC is installed,and the vibration reduction effect of the RC can be improved by using the design method of the parameter correction of the curve area.[Conclusions] The rational design of the RC's parameters can produce a vibration isolating system with excellent vibration isolation effects.

针对双层气囊隔振装置高精度姿态平衡控制需求,提出多目标协同姿态控制方法.通过建立双层隔振装置动力学模型、充放气控制等效作用力模型,建立了控制响应特性分析模型.并基于多目标满意优化方法建立了多目标协同姿态控制方法,使得双层气囊隔振装置能够较好地适应上下层气囊隔振装置姿态耦合,实现姿态平衡控制,并可有效抑制结构弹性变形对姿态平衡控制的影响.在双层气囊隔振装置上验证了该控制方法的可行性.该方法将用于某型船舶大型发电机组双层气囊隔振系统,实现双层气囊隔振装置柔性支撑状态下的姿态平衡控制.

文章以汽车主动悬架为研究对象,结合二自由度非线性汽车主动悬架动力学模型,利用微分几何理论将非线性模型精确线性化后,首先设计PID控制器,为抑制干扰因素影响而引起系统参数或结构改变,提高悬架系统应对复杂工况下的自适应能力,然后设计了利用模糊控制原理对PID参数进行在线整定的自适应模糊PID控制器.仿真结果表明:相比于参数固定的被动悬架系统,采用该控制方法的主动悬架能够轻松应对各种工况,不仅在保证改善汽车乘坐的舒适性的情况下,同时进一步改善了车辆的行驶平顺性和行驶安全性,为汽车主动悬架系统控制策略设计提供实用性参考.

文章将常见滑坡模型进行简化,把滑体的运动状态分为失稳启动后斜面运动阶段和水平运动阶段.通过FIS H语言编写PFC3D颗粒流运行程序,模拟并分析了滑体从开始解体到运动停止堆积状态的整个运动过程.考察滑体在不同时刻的运动形态变化,记录了滑体内部颗粒接触数目与滑体能量随时间变化的规律.通过在相关特征部位设定监测点,获得滑体不同部位的总速度、纵向速度和纵向位置等运动特征参量.结果表明:滑体各部分运动状态受所处的初始位置影响很大;滑体颗粒不光有前后运动还有横向运动;滑体中不同能量变化差异较大.

为了改善主机的抗冲击性能,首先基于气囊限位装置的动力学模型,理论分析了系统响应峰值随限位器的间隙 、刚度参数变化的趋势;然后,采用数值仿真的方法分析了限位器间隙 、刚度 、阻尼比和橡胶层厚度对主机隔振系统抗冲击性能的影响,并对主机气囊隔振系统的限位参数进行了设计,结果表明:通过气囊隔振装置限位参数的优化设计,可明显降低主机的冲击响应.

A finite element model of a ship integrated isolation system is established and the concept Bearing load-increment (BLI) is proposed to quantificationally analyze the shafting static characteristics. The BLI under different propeller thrusts and trimming conditions are calculated. The results show that the two conditions can generate several tons of BLI. The influence of parameters including thrust bearing stiffness, thrust acting position and isolator supporting position are researched, which reveals that they are in favor of reducing the BLI for increasing the thrust bearing stiffness, centralizing the thrust to the mass center of the raft, and locating the supporting isolators on the stem part of the raft.

针对新型舰船大功率密度推进电机低频隔振系统有限元实体建模计算代价大 、结构尺寸不定等难题,以某新型推进电机隔振系统设计校核为背景,通过在有限元软件中建立隔振系统简化模型,分析了系统模态 、船舶不同姿态下 、主机不同工况下轴系对中校核.分析结果与理论模型的对比结果证明:基于有限元简化模型的船舶主机隔振系统研究方法简便可行,可为复杂隔振系统的设计及理论分析提供一种新的建模方法.

Based on Integrated Vibration Isolator (IVI) of marine's thrust bearing, it has focus on the coupling vibration between IVI and thrust bearing when the boundary of marine shafting has changed. In the paper, the analytic expressions of longitudinal and whirling transfer matrix of IVI have been derived in detail, and the three dof's coupling vibration model in Xoz plane of IVI and thrust bearing has also been established. Then combined with the parameters of IVI built in author's laboratory, it put emphases on longitudinal and whirling coupling vibration of marine shafting with elastic support of thrust bearing which is caused by the asymmetry of IVI's stiffness matrix. Furthermore, the coupling vibration mentioned above partly decreases the damping band of IVI with the force transmissibility as the evaluating indicator.

Wave glider is an innovative equipment in recent years, which uses ocean energy as its power. It has signific-ant value in research and application in both civil and military aspects. In this paper, the CAD-CFD integration platform Friendship Framework is used, which is unique in the field of ship design. By using its secondary development function Fea-ture, the parametric modeling method of the surface boat of wave glider is researched. On this basis, the Sobol optimization algorithm helps in the optimization calculation on multiple plans and the analysis on the important parameter affecting the resistance. At the same time, a preliminary analysis on the range of location of gravity and suspension point is made. Through the optimization design, the surface boat's speed and resistance is significantly improved, and the optimization pro-cess is proved valid by STAR-CCM+. This method provides a useful way to the quick design on the surface boat of wave glider.

With the integrated vibration isolation system (IVIS) of thrust bearings in ships as the engineering background, the IVIS and the longitudinal shafting system coupled model are established by using the transfer matrix method. The dynamic characteristics of the shafting with elastic support of thrust bearing are studied. The analysis is focused on the damping capability of the IVIS for blade frequency and multiple blade frequency of the propeller. And the corresponding test is done on a test rig. The results show that IVIS can effectively attenuate the low frequency vibration of the thrust bearing and the vibration can be reduced by 14.4 dB under 15 Hz excitation. Meanwhile, longitudinal displacement of the IVIS can meet the operation safety requirement of shafting, which is nearly 0.4 mm with the action of the thrust of 100 kN.

Based on integrated vibration isolation system (IVIS) of thrust bearing in ships,the coupling alignment model of IVIS and marine shafting is established.And combined with a certain marine shafting's parameters,the influence on shafting alignment of radial displacement of thrust bearing under different marine working conditions is analyzed.The results show that the thrust bearing's radial displacement of IVIS would greatly change the load state of bearings,and the void phenomenon would appear at extreme conditions.So the axial installation position of the base of thrust bearing on the floating raft should be close to the center of rotation of IVIS.Meanwhile the exploratory development on the adaptability of existing shafting scheme is carried out,and it is founded that the improved scheme of shafting could accommodate 0.55 mm radial displacement of thrust bearing after the cold and hot deformation of bearings.

Based on the theory of elastic wave in structure, through the established longitudinal vibration model of the shafting which takes thrust bearing and its supporting system as one boundary condition, the frequency characteristic equation of longitudinal vibration was derived and the first-order natural frequen-cy with Taylor series was estimated. Then combined with a certain ship parameters, the comparative re-search on the isolation effect of shafting longitudinal vibration between Integrated Vibration Isolator and Resonance Charger was put. The results show that the effect of Integrated Vibration Isolator could be bet-ter in large frequency bands, while RC more performance characteristics of DVA; furthermore, on the basis of safety operation of the shafting, larger damping frequency bands could be acquired with more weight of In-tegrated Vibration Isolator and less of RC.

Objective To discuss the clinical efficacy of transcatheter arterial embolization in the treatment of acute renal arte-rial original hematuria.Methods All of he 55 patients with acute renal artery original hematuria underwent renal angiography were analyzed retrospectively, referring to the difrrent angiographic manifestations, superselective renal arterial embolization by u-sing two kinds of embolic agents such as embosphere microspheres and the ciols.Results After superselective renal arterial em-bolization, 53 cases of the gross and microscopic hematuria were disappeared within 24 hours;1 case after interventional embolism continued conservative treatment two week later, the gross hematuria disappeared;1 case was failed after interventional embolism, then surgical resection was performed.After embolization, all the patients were followed up for about 6 to 12 months.The total ef-fective rate was 96.36%(53/55).Conclusion The therapeutic effect transcatheter arterial superselective embolization in the treatment of acute renal arterial original hematuria is significant, and appropriately using permanent embolization agents can not only effectively stop the bleeding but also preserve the normal renal tissue and renal function to the greatest possible advantage.

推力轴承传递的螺旋桨动态激励力可激发船体结构振动,是舰船重要的机械噪声源.采取弹性支承方式可降低推力轴承引起的噪声,但在受冲击载荷作用时,弹性支承的变形会导致推力轴承与轴系之间产生相对位移,从而影响轴系运行安全.为分析弹性支承推力轴承的抗冲击性能,文章建立了推进轴系及弹性支撑推力轴承和主机耦合模型,采用仿真分析方法研究了推力轴承的冲击响应.分析结果表明,推力轴承的相对位移响应较大,近似等于最大许用位移值,通过改变隔振器刚度、支撑轴承刚度与位置等措施,可使推力轴承的相对位移响应满足舰船设备抗冲击要求,并改善轴系受力状态.

Taking an ultra-slender trimaran as an example,the loads response in irregular waves is calculated.And arrangement of side hulls is optimized considering the influence of speeds.The results show that the distribution of longitudinal bending moments demonstrates the assumption of hull girder.As the trimaran is much wider than the conventional single hull ships,it can also be assumed as a beam simply supported at both ends along the ship breadth.The relative position of side hull does not affect the encounter wave frequency,but affects the wave load response amplitude.When the arrangement of side hulls is optimized,the high service speeds need tobe considered