应用余能原理求解渐变刚度钢板弹簧

本文应用余能原理和δ函数推导出两片阶梯形轮廓渐变刚度钢板弹簧的一组计算公式，为完善多片渐变刚度板弹簧的设计计算提供了理论依据。     

东风_4型内燃机车转向架组合弹簧的优化设计

根据强度分析,东风_4型内燃机车转向架组合弹簧的静强度不足.本文采用惩罚函数法对该组合弹簧进行优化设计,从而提出较好的设计方案.     

形状记忆合金弹簧变形分析及其在振动控制中的应用

对Brinson的本构模型作了适当的修正,建立了适用于形状记忆合金弹簧的本构模型。基于该本构关系,还进行了形状记忆合金弹簧的变形分析,可以看出SMA弹簧在不同的状态下,其刚度也不同,这样可通过改变SMA弹簧的刚度来改变系统的共振频率。     

少片簧优化设计

通过举例和理论计算分析少片簧的片数、长度和应力状态对少片簧质量的影响,指出在少片簧设计中其产品质量与应力状态成反比关系,与其片数和长度无关系,进而得出在少片簧设计中提高设计应力和选择较少片数和较短长度是生产成本最低、质量最轻的优化设计方法。     

Theme Issue 30(2): "Economics of Marine Protected Areas"

Most Florida manatees depend on localized warm-water refuges in the southern two-thirds of Florida to survive winter; about 60% use outfalls from 10 power plants, whereas 15% use 4 natural warm-water springs. Future availability of these refuges is in doubt; most of these power plants may be retired within the next 20 years and groundwater withdrawals for human use threaten natural springs. This article examines possible effects on manatees from losing major warm-water refuges and alternative management actions. Because of manatee site-fidelity patterns, plant retirements may increase cold-stress-related deaths and significantly decrease manatee abundance. A forward-looking management strategy is urgently needed before decisions are made to retire plants now used by large numbers of manatees. Possible management alternatives include: gradually weaning manatees off plant outfalls, maintaining the flow of springs now used by manatees, enhancing access to suitable warm-water springs now little used or unused by manatees, constructing new non-industry dependent warm-water refuges, and creating new thermal basins to retain warm-water pockets able to support overwintering manatees.