由于时间限制,常常使特殊用途的曲轴不能设计得最佳。用经验法则和应力集中类比方法的技术必然使求得的未知量偏于保守。“截割和试凑”(Cutandtry)方法不能在较理想的时间内得到所需要的数据。缺乏优化,不仅导致曲轴本身,而且使整个柴油机价格过高,重量和尺寸过大。因而须要一个既正确又经济的方法,使曲轴设计在最短的时间内,利用几何迭代而收敛于最后形状。设计者决定外形、圆角应力和近似地估计曲轴刚度时所需要的原始数据,通常难于准确地确定。 Due to time constraints, special purpose crankshafts are often not designed optimally. The technique of using the rule of thumb and the stress-concentration analogy inevitably makes the unknowns to be conservative. The Cut andtry method does not get the data you need in an ideal time. Lack of optimization not only leads to the crankshaft itself, but also makes the entire diesel engine too expensive, too heavy and too large in size. There is therefore a need for a correct and economical method of making the crankshaft design converge to the final shape with geometric iterations in the shortest amount of time. It is often difficult to accurately determine the raw data required by the designer to determine the shape, fillet stress, and approximate crankshaft stiffness.