整车制造业中,物流是非增值环节,物流成本的削减可以为企业赢取更高的边际利润。为了降低厂内生产物流成本,准时化生产(JIT,Just in Time),排序拉动生产(JIS,Just in Sequence),物流服务外包等模式应运而生。文章以北京奔驰后驱车工厂为...整车制造业中,物流是非增值环节,物流成本的削减可以为企业赢取更高的边际利润。为了降低厂内生产物流成本,准时化生产(JIT,Just in Time),排序拉动生产(JIS,Just in Sequence),物流服务外包等模式应运而生。文章以北京奔驰后驱车工厂为例,对厂内的生产物流作业成本进行研究。以零件进入车间为起点,以最小化厂内物流作业成本为目标,综合考虑实际生产约束,搭建收货、入库、出库和配线四大厂内物流作业成本优化模型并成功应用,既实现了本企业生产运营成本的节约,也为其他汽车企业的厂内物流成本优化提供借鉴思路。展开更多
Dynamic compression tests were carried out to investigate dynamic mechanical behavior and adiabatic shear bands in ultrafine grained(UFG)pure zirconium prepared by equal channel angular pressing(ECAP)and rotary swayin...Dynamic compression tests were carried out to investigate dynamic mechanical behavior and adiabatic shear bands in ultrafine grained(UFG)pure zirconium prepared by equal channel angular pressing(ECAP)and rotary swaying.The cylindrical specimens were deformed dynamically on the split Hopkinson pressure bar(SHPB)at different strain rates of 800 to 4000s^-1 at room temperature.The temperature distribution of the shear bands was estimated on the basis of temperature rise of uniform plastic deformation stage and thermal diffusion effect.The results show that the true stress-true strain curves of UFG pure zirconium are concave upward trend of strain in range of 0.02-0.16 due to the effects of strain hardening,strain rate hardening and thermal softening.The formation of the adiabatic shear bands is the main reason of UFG pure zirconium failure.A large number of micro-voids are observed in the adiabatic shear bands,and the macroscopic cracks develop from the micro-voids coalescence.The fracture surface of UFG pure zirconium exhibits quasi cleavage fracture with the characteristic features of shear dimples and river pattern.The highest temperature within the shear bands of UFG pure zirconium is about 592 K.展开更多
文摘整车制造业中,物流是非增值环节,物流成本的削减可以为企业赢取更高的边际利润。为了降低厂内生产物流成本,准时化生产(JIT,Just in Time),排序拉动生产(JIS,Just in Sequence),物流服务外包等模式应运而生。文章以北京奔驰后驱车工厂为例,对厂内的生产物流作业成本进行研究。以零件进入车间为起点,以最小化厂内物流作业成本为目标,综合考虑实际生产约束,搭建收货、入库、出库和配线四大厂内物流作业成本优化模型并成功应用,既实现了本企业生产运营成本的节约,也为其他汽车企业的厂内物流成本优化提供借鉴思路。
基金Funded by National Natural Science Foundation of China(No.51474170)Natural Science Foundation of Shaanxi Province(No.2016JQ5026)Foundation of Liaoning Province Educational Committee(No.2017LNQN14).
文摘Dynamic compression tests were carried out to investigate dynamic mechanical behavior and adiabatic shear bands in ultrafine grained(UFG)pure zirconium prepared by equal channel angular pressing(ECAP)and rotary swaying.The cylindrical specimens were deformed dynamically on the split Hopkinson pressure bar(SHPB)at different strain rates of 800 to 4000s^-1 at room temperature.The temperature distribution of the shear bands was estimated on the basis of temperature rise of uniform plastic deformation stage and thermal diffusion effect.The results show that the true stress-true strain curves of UFG pure zirconium are concave upward trend of strain in range of 0.02-0.16 due to the effects of strain hardening,strain rate hardening and thermal softening.The formation of the adiabatic shear bands is the main reason of UFG pure zirconium failure.A large number of micro-voids are observed in the adiabatic shear bands,and the macroscopic cracks develop from the micro-voids coalescence.The fracture surface of UFG pure zirconium exhibits quasi cleavage fracture with the characteristic features of shear dimples and river pattern.The highest temperature within the shear bands of UFG pure zirconium is about 592 K.
