Mathematical model validated by a crash test for studying the occupant’s kinematics and dynamics in a cars’ frontal collision

The aim of the paper was to determine the kinematic parameters that influence the occupant injury risk through a mathematical model. The developed model is a 2D model composed of 4 bodies (2 vehicles, thorax and head). The head and thorax are interconnected with a rotation joint and a torsion spring meant to stiffen the relative movement between the bodies. The thorax is connected with the vehicle body by a linear spring meant to simulate the seatbelt stiffness. The model was solved using Lagrange principle and the validation of the model was made through a crash test performed using the same initial conditions and comparing the obtained values of the displacement, velocity and acceleration parameters with the ones obtained with the mathematical model. The head and torso were chosen due to the fact that they are the common parts of the body that get injured, especially the head with the change of 80 % to cause fatal injury in car’s frontal collision. Once the model was validated, the stiffness of the seatbelt was modified in order to determine the behavior of the occupant in case of car frontal collisions. When the seatbelt stiffness was reduced, the occupant displacement and velocity increased, while by increasing the stiffness, these parameters decreased. The values of the developed model presented a high degree of similarity with the results obtained from the crash test with an error of 10 %. This model can be used by engineers to easily asses the occupant injury risk in case of vehicle frontal collisions.     

Flexural gravity wave generation by initial disturbances in the presence of current

The effect of uniform current on the generation of flexural gravity waves resulting from initial disturbances at a point was analyzed in two dimensions. The problem was formulated as an initial boundary value problem under the assumptions of the linearized theory of water waves. By direct application of the Laplace transform and then the Fourier transform, explicit expressions for the velocity potential and free surface elevation were obtained in integral forms; these were evaluated asymptotically for large distances and times by the application of the method of the stationary phase to obtain the far field behavior of the surface elevations in specific cases. Simple numerical computations were performed to illustrate the effect of uniform current on the surface elevation, wavelength, phase velocity, and group velocity of the flexural gravity waves and on the far field behavior of the progressive waves in two different cases, namely, when there is an initial depression concentrated at the origin and an initial impulse concentrated at the origin.     

Optimal scheduling of the flexray static segment based on two-dimensional bin-packing algorithm

FlexRay is a reliable and hard real-time in-vehicle communication protocol that is strongly promoted by car manufacturers as the de facto standard in the automotive domain. The protocol offers both a time-triggered and an eventtriggered architecture. This paper focuses on the optimal scheduling of the time-triggered component of FlexRay known as the static (ST) segment using a two-dimensional bin-packing technique. To maximize the bandwidth utilization in the ST segment, a fast heuristic as well as an efficient integer linear programming approach are proposed. Our methods directly schedule signals into slots including frame packing, according to signal-based data scheduling and the slot/ cycle multiplexing mechanisms presented by the latest version of the FlexRay protocol. The benefits of our proposed methods are demonstrated by extensive experiments on synthetic and an automotive X-by-wire system case study. An additional test case is examined to emphasize the superior performance of the proposed approach relative to that of existing optimal scheduling approaches.     

Damage Accumulation in Rail Steel under Rolling with Slippage and Its Analysis

Experimental research results of surface damage accumulation in rail steel under rolling with slippage are presented. Hertz contact for two rollers made of rail and wheel steels was realized in the test. The influence of loading regime upon wear of rail is considered. The estimation of characteristics of surface fracture resistance for rail steel is made. The method to predict the life of rail steel under given conditions of regular loading is proposed.     

对《玻璃纤维增强塑料渔船建造规范（1995）》的意见

我国最早的<玻璃纤维渔船建造规范>出自于1989年,为试行本,后经过一系列修改而成1995年版<玻璃纤维增强塑料渔船建造规范>(以下简称<95玻璃钢渔规>)使用至今.随着建造玻璃钢渔船数量的增加,不断地探索与经验积累,在<95玻璃钢渔规>的应用中发现仍有许多值得研究与探讨的地方.     

我国国际工程承包业的地位和发展

分析了国际工程承包市场的现状与发展趋势，以及我国在国际工程承包市场中的地位，指出了我国国际工程承包业需要解决的问题，并提出了促进其发展的建议。     

电流变流体的润滑性能研究

提出了电流变流体作为润滑剂使用的新设想，研究了电流变流体粘度的可控特性，通过试验获得了电流变流体摩擦力随电场强度、悬浮颗粒浓度、油膜厚度等因素的变化规律，为深入研究电流变流体的润滑特性奠定了基础。     

随机变分方程解的存在,唯一性问题

研究了随机有限元方法的理论基础－随机变分方程解的合理性问题，证明了一般形式的随机变分方程解的存在与唯一性定性，明确了在随机扰动算子不足以破坏均值微分算子的强制性条件－不会导致方程类型变异的前提下，Ｆｒｅｄｈｏｌｍ择一定理的第二个结果成立，此时在概率１的意义上变分解存在而且唯一。     

CRTSⅢ型路基纵连轨道板制造技术及创新

成灌铁路采用了全新的CRTSⅢ型无砟轨道结构,在路基地段敷设了CRTSⅢ型路基纵连轨道板。介绍了CRTSⅢ型路基纵连轨道板的结构特点、二雏可调钢模技术、自动调整测量系统、生产工艺及检测方法,并总结了该种轨道板的主要创新点。