摘要：Bacterial infection is a major problem following bone implant ***,poly-l-lactic acid/carbon nanotube/hydroxyapatite(PLLA/CNT/HAP)bone scaffolds possess enhanced mechanical properties and show good ***,wesynthesizedsilver(Ag)-dopedCNT/HAP(CNT/Ag-HAP)nanohybrids via the partial replacing of calcium ions(Ca2+)in the HAP lattice with silver ions(Ag+)using an ion doping technique under hydrothermal ***fically,the doping process was induced using the special lattice structure of HAP and the abundant surface oxygenic functional groups of CNT,and involved the partial replacement of Ca2+in the HAP lattice by doped Ag+as well as the in situ synthesis of Ag-HAP nanoparticles on CNT in a hydrothermal *** result-ing CNT/Ag-HAP nanohybrids were then introduced into a PLLA matrix via laser-based powder bed fusion(PBF-LB)to fabricate PLLA/CNT/Ag-HAP scaffolds that showed sustained antibacterial *** then found that Ag+,which pos-sesses broad-spectrum antibacterial activity,endowed PLLA/CNT/Ag-HAP scaffolds with this activity,with an antibacterial effectiveness of 92.65%.This antibacterial effect is due to the powerful effect of Ag+against bacterial structure and genetic material,as well as the physical destruction of bacterial structures due to the sharp edge structure of *** addition,the scaffold possessed enhanced mechanical properties,showing tensile and compressive strengths of 8.49 MPa and 19.72 MPa,***,the scaffold also exhibited good bioactivity and cytocompatibility,including the ability to form apatite layers and to promote the adhesion and proliferation of human osteoblast-like cells(MG63 cells).

摘要：Blades are one of the important components on aircraft *** they break due to vibration failure,the normal operation of the entire engine will be ***,it is necessary to measure their natural frequency before installing them on the engine to avoid *** present,most blade vibration testing systems require manual operation by operators,which has high requirements for operators and the testing process is also very ***,the testing efficiency is low and cannot meet the needs of efficient *** solve the current problems of low testing efficiency and high operational requirements,a high-precision and high-efficiency automatic test system is *** testing accuracy of this system can reach ±1%,and the testing efficiency is improved by 37% compared to manual ***,the influence of compression force and vibration exciter position on natural frequency test is analyzed by amplitude-frequency curve,so as to calibrate servo cylinder and fourdimensional motion ***,the sine wave signal is used as the excitation to sweep the blade linearly,and the natural frequency is determined by the amplitude peak in the frequency ***,the accuracy experiment and efficiency experiment are carried out on the developed test system,whose results verify its high efficiency and high precision.

摘要：在车载炮驾驶室拓扑优化设计和刚强度分析计算中,需要明确大量的、不同射击条件下的冲击载荷.如何快速获取驾驶室表面的冲击载荷是车载炮设计中尚未解决的难题之一.本文将深度学习方法引入到驾驶室表面冲击载荷的求解中,基于卷积-多维特征LSTM神经网络,提出了一种驾驶室表面冲击载荷快速预测方法,实现了不同发射条件下驾驶室表面冲击载荷计算,求解速度接近实时级别.算例结果表明,深度学习模型的求解精度与传统CFD仿真精度相当,但求解耗时在毫秒级,大大提高了计算效率,具备离线训练、在线计算的潜力.且当驾驶室形貌特征轻微变化时,本文模型依然适用.本文成果可快速为驾驶室刚强度校核和拓扑优化提供载荷条件,有助于缩短车载炮研发周期,为车载炮系统的数字孪生模型构建奠定了基础.

摘要：为了解决三维空间中的非线性动力学问题,本文提出了一种新的等几何实体单元,并通过张量分析中的坐标变换得到其非线性应变场.为了使所提出的单元能够无缝地应用于计算机辅助设计(CAD)和计算机辅助工程(CAE)系统中,采用三变量T样条作为等几何实体单元的基函数.借助Bézier投影法,提出了基于T样条的等几何实体单元的局部网格更新算法.在重要区域对网格进行局部细化以获得准确的结果,在重要区域以外对冗余单元进行粗化以提高计算效率.因此,非线性动力学分析中的计算效率和计算精度得到了平衡.三个静力学数值算例验证单元弹性模型的正确性.通过柔性摆仿真算例研究该单元的动力学特性.通过实验测试该单元解决非线性动力学实际问题的能力.应用局部网格更新算法进行柔性摆与障碍物碰撞接触的仿真.通过对计算结果和计算耗时的分析,研究基于局部变网格T样条的实体单元在非线性动力学问题中的有效性.

摘要：A good cooling circle should ensure that the system can work at an appropriate temperature in the requirements of power increase,engine compartment constraint and working demands for modern engineering machinery,which asks for a thorough understanding of system thermal loads before practical ***,traditional experiment method spends a long time,costs a huge resource but lacks efficiency,whereas virtual design can avoid the shortcomings of traditional method and can analyze operating states adequately with variable loads on engine,generator,drives,battery pack and HVAC ***,this paper focuses on a new virtual design method based on multi-dimension coupled simulation adopting Flowmaster software for initial prediction and CFX tool for further *** simulation results in different operating conditions are compared and validated with *** experiment and range analysis are used to explore key parameters of cooling *** research will be helpful in guiding future design and optimization of engineering machinery.

摘要：The numerical simulation on drawing process of automotive B-pillar was carried out on AutoForm software,and dangerous forming areas were *** processing parameters,such as the layout of drawbeads,blank holding force and the shape of blank,were adjusted and optimized according to the simulation *** indicate that the quality defects can be forecast and removed,which improves the stability of forming *** cost of design is decreased and the research cycle is *** is proved that the drawing process and die design of B-pillar forming are feasible in actual production.

摘要：为一般不明确的非线性的时间延期系统的柔韧的稳定控制器的系统的递归的设计方法在这份报纸被调查。一条延期无关的州的反馈控制法律能被递归地构造 Lyapunov-Razumikhin 功能获得。以便柔韧的稳定控制法律的设计没有为系统的任何限制，由一些设计技术，对 Razumikhin 条件的应用程序内在的障碍才能被移开。

摘要：Many kinds of devices with cam have been widely used in various mechanical equipments. However, non-equalization machining for spatial cam trough remains to be a difficult problem. This paper focuses on the analysis of running conditions and machining processes of spatial cam with oscillating follower. We point out the common errors in the biased distance cutting. By analyzing the motion of oscillating follower of spatial cam, we present a new 3D curve expansion model of spatial cam trough-outline. Based on this model, we have proposed a machining method for trochoidal milling with non-equalization diameter cutter. This new method has led to a creative and effective way for non-equalization diameter machining for spatial cam with oscillating follower.

摘要：Because of its ease of implementation,a linear PID controller is generally used to control robotic *** controllers cannot effectively cope with uncertainties and variations in the parameters;therefore,nonlinear controllers with robust performance which can cope with these are *** sliding mode control(SMC)is a robust state feedback control method for nonlinear systems that,in addition having a simple design,efficiently overcomes uncertainties and disturbances in the *** also has a very fast transient response that is desirable when controlling robotic *** most critical drawback to SMC is chattering in the control input *** solve this problem,in this study,SMC is used with a boundary layer(SMCBL)to eliminate the chattering and improve the performance of the *** proposed SMCBL was compared with inverse dynamic control(IDC),a conventional nonlinear control *** kinematic and dynamic equations of the IRB-120 robot manipulator were initially extracted completely and accurately,and then the control of the robot manipulator using SMC was *** validation,the proposed control method was implemented on a 6-DOF IRB-120 robot manipulator in the presence of *** results were simulated,tested,and compared in the MATLAB/Simulink *** further validate our work,the results were tested and confirmed experimentally on an actual IRB-120 robot manipulator.

摘要：V-shape hulls are widely used in peacekeeping efforts such as demining vehicles in order to deflect the blast energy and reduce the effects of mine blast. Blast resistant design and energy absorption enhancement of V-shape plates were carried out using finite element analysis package ABAQUS. Various geometries of V-shape plates with and without interlayer of materials like Al-foams and honeycomb were employed to analyze their effects on the deformation of the plate and applied stresses and strains. The results obtained show that application of metallic foams leads to better response of the plate and consequently results in more energy dissipation, less dame to vehicle and enhances crew survivability.