巴彦浩特盆地构造样式分析及其意义

巴彦浩特盆地是在早古生代早期的秦、祁、贺三叉裂谷系交岔带发育起来的复合－叠加型盆地。由于其所处的特殊的构造位置和复杂的构造演化历史,使盆地发育了丰富多样的构造样式：压缩构造样式主要有叠瓦状冲断层、背冲、对冲构造组合、牵引背斜、滚板构造等;伸展构造样式主要有铲形正断层与掀斜断块、反向断层与滚动背斜、“垒－堑”构造等;走滑构造样式主要有花状构造、雁列断层等;另外,还有与重力等其它因素有关的构造样式发育,如压实构造、底辟构造等。不同的构造样式伴生有不同的油气圈闭类型,综合分析石油地质条件认为：黑汕托－通古楼背斜构造带为最有利构造带,阿门子－查汗背斜构造带次之,并预测该盆地具有良好的油气勘探前景。     

A parametric study of golf car and personal transport vehicle braking stability and their deficiencies

This paper describes research and parametric analyses of braking effectiveness and directional stability for golf cars, personal transport vehicles (PTVs) and low speed vehicles (LSVs). It is shown that current designs, which employ brakes on only the rear wheels, can lead to rollovers if the brakes are applied while traveling downhill. After summarizing the current state of existing safety standards and brake system designs, both of which appear deficient from a safety perspective, a previously developed dynamic simulation model is used to identify which parameters have the greatest influence on the vehicles’ yaw stability. The simulation results are then used to parametrically quantify which combination of these factors can lead to yaw induced rollover during hard braking. Vehicle velocity, steering input, path slope and tire friction are all identified as important parameters in determining braking stability, the effects of which on rollover propensity are presented graphically. The results further show that when vehicles are equipped with front brakes or four-wheel brakes, the probability of a yaw induced rollover is almost entirely eliminated. Furthermore, the parametric charts provided may be used as an aid in developing guidelines for golf car and PTV path design if rear brake vehicles are used.     

ROBUST DESIGN FOR IMPROVED VEHICLE HANDLING UNDER A RANGE OF MANEUVER CONDITIONS

In this article, a robust design procedure is applied to achieve improved vehicle handling performance as an integral part of simulation-based vehicle design. Recent developments in the field of robust design optimization and the techniques for creating global approximations of design behaviors are applied to improve the computational efficiency of robust vehicle design built upon sophisticated vehicle dynamic simulations. The approach is applied to the design of a M916A1 6-wheel tractor/M870A2 3-axle semi-trailer. The results illustrate that the proposed procedure is effective for preventing the rollover of ground vehicles as well as for identifying a design that is not only optimal against the worst maneuver condition but is also robust with respect to a range of maneuver inputs. Furthermore, a comparison is made between a statistical approach and a bi-level optimization approach in terms of their effectiveness in solving robust design problems     

翻车保护结构侧向加载的仿真分析与设计方法

提出了利用NX Nastran6.0软件的材料非线性有限元仿真功能,模拟翻车保护结构(Roll-over Protective Structures,简称ROPS)侧向加载的试验室试验过程,获得侧向位移量、侧向载荷能量等数据,使ROPS符合有关标准要求的设计方法.并提出用满足侧向载荷能量时的侧向作用力,在标准要求最小值...     

基于动态稳定性的汽车侧翻预警

为提高汽车侧翻预警算法的实时性及动态过程侧翻预警的精度,提出基于动态稳定性的汽车侧翻预警算法。考虑车轮侧倾外倾和侧倾转向及悬架变形外倾和变形转向对轮胎侧偏特性的影响,建立多自由度汽车侧翻动力学模型;应用汽车侧翻动力学理论及劳斯稳定性判据获得汽车侧翻动平衡稳定条件及汽车侧翻动平衡状态的抗干扰稳定条件,并提出侧翻动态稳定因子作为汽车动态稳定性的评价指标;融合汽车侧翻预警机理及侧翻动态稳定因子设计出基于动态稳定性的汽车侧翻预警算法;针对高速紧急工况下运动型多功能车侧翻过程进行动态侧翻预警仿真分析。结果表明,基于动态稳定性的汽车侧翻预警算法预警结果准确、实时,可提高动态过程汽车侧翻预警精度,降低侧翻危险的误报警率,有助于改善汽车防侧翻的主动安全性能。     

台阶形锻件焖锻成形新析

通过分析焖锻成形工艺，对该工艺过程中可能出现的缺陷进行了进一步的分析探讨，并提出了相应的预防措施。     

Trends in tractor related fatalities among adults working on farms in Victoria,Australia, 1985–2010

Tractors are associated with more fatalities than any other piece of machinery in agriculture, with tractor rollovers being a frequent mechanism. This study examines tractor fatalities between 1985 and 2010 in Victoria, Australia, and examines the impact of the 1998 legislation mandating the retrofitting of rollover protection structures (ROPS). The data source was the Victorian WorkCover Authority to whom unintentional work placed deaths are reportable. During the study period, 121 tractor fatalities occurred, of which 55 were rollovers. Poisson regression modelling indicated a significant decline in rollover fatalities during this period of approximately 7% per annum (incidence rate ratio [IRR] = 0.93, 95% CI 0.90–0.97), however there was no simple relationship between the introduction of the legislation and the fatality decrease. It is proposed that the impact of previous voluntary retrofitting initiatives, coupled with the existing requirement for ROPS on new tractors, may have increased ROPS fitment to a critical point prior to the final requirement for retrofitting, diluting the effect over a number of years so that it could not be detected using the statistical techniques that have been applied. An increased trend in run over fatalities was also found (IRR = 1.04, 95% CI 1.00–1.09) suggesting the need for research into interventions for this type of fatality, such as safe tractor access platforms.     

基于车辆侧倾角侧翻预警算法的研究

侧翻预警是防止运输车辆发生事故的主要手段。基于车辆侧倾角和侧向加速度的监测,建立车辆动态侧翻模型,设计侧翻事故线性判别函数,提出了直接根据侧倾角信号和侧向加速度信号对侧翻事故进行判断的预警算法。通过对某车型进行仿真试验验证了预警算法的有效性,同时本算法具有计算量小、计算速度快等优点,对减少同类交通事故的发生具有重要意义。     

Numerical analysis of void-induced thermal effects on GaAs/AlxGa1−xAs high power single-quantum-well laser diodes

Microscopic voids in the die attachment solder layers of high power laser diodes (HPLDs) cause to degrade their overall thermal transfer performance. This paper presents the effects of voids on the thermal conductivity, leakage and threshold currents, characteristic temperature (T₀) and output power of a single quantum well (SQW) HPLD. These effects are modeled by means of finite difference method (FDM). This numerical model calculates the time-dependent axial variations of photon density, carrier density and temperature in semiconductor laser self-consistently. The temperature dependence of the wavelength shift and the thermal mode hopping phenomenon is also demonstrated.     

商用车辆采用低速试验数据判断动态车辆侧翻的临界值

已经开发了一个确定动态车辆侧翻临界值的方法,该方法采用一侧翻平面车辆模型和以低速进行试验测量的侧向加速度为基础仿真。然后采用曲线拟合技术推断侧向加速度和前进速度的临界值。该方法采用变通道运动试验证实,并获得一个良好的相互关系。本方法很好适应确定侧翻临界值一目标试验程序,仅需要测量侧向加速度。