世界机床市场综述

据《美国机械师》最近报道,1993年,世界机床生产比上年减少17.1％,下降了58亿美元,只有282亿美元。这是继1992年机床减产19％后世界机床史上第二次大幅度下降。与此同时,向非工业国家的机床出口下降了20％,不到机床产量的9％。

ASME Section Ⅲ Stress Analysis of a Heat Exchanger Tubesheet with a Misdrilled Hole and Irregular or Thin Ligaments

A stress analysis is described for a nuclear steam generator tubesheet with a thin, or irregular ligament, associated with a mis-drilled hole using the rules of ASME （American Society of Mechanical Engineers） B ＆ PV Section Ⅲ and non-mandatory Appendix A, Article A-8000 for stresses in perforated flat plates. The analysis demonstrates the proper application of the NB-3200 rules for this special application, with discussion of the differences between an actual tube hole deviation and what is assumed in ASME Appendix A. This is a companion paper to ＂Technical Justification Supporting Operation with a Tube Installed in a Mis-Drilled Hole of a Steam Generator Tubesheet＂.

世界机床市场结束三年滑坡转机再现

据今年五月《美国机械师》杂志公布的统计数字,1994年世界机床消费额为261.71亿美元,比1993年下降仅1.2％;产值为289.95亿美元,比上年仅下降0.22％;出口额为166.38亿美元,比上年增加了9.4％;进口额为138.14亿美元,比上年上升了9.2％。这些数字表明。