DIN EN 301239-1999 数字无绳电信(DECT).数据服务分布图(DSP).封闭式用户组的同步数据传送服务(服务类型D,移动等级1)

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【英文标准名称】:Hexagonheadscrews;productgradeC(ISO4018:1988);germanversionEN24018:1991
【原文标准名称】:全螺纹六角头螺栓.产品等级C(ISO4018-88)
【标准号】:DINEN24018-1992
【标准状态】:作废
【国别】:德国
【发布日期】:1992-02
【实施或试行日期】:
【发布单位】:德国标准化学会(DIN)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:六角头螺钉;紧固件;规范(审批);尺寸;名称与符号;交货条件;螺栓;螺纹;螺钉;验收规范
【英文主题词】:bolts;fasteners;screws(bolts);dimensions;designations;acceptancespecification;threads;specification(approval);hexagonheadscrews;deliveryconditions
【摘要】:
【中国标准分类号】:J13
【国际标准分类号】:3920
【页数】:8P;A4
【正文语种】:德语


Product Code:SAE AIR1387
Title:Designing With Elastomers for Use At Low Temperatures, Near Or Below Glass Transition
Issuing Committee:Ams Ce Elastomers Committee
Scope:To ensure success in design of elastomeric parts for use at low temperature, the design engineer must understand the peculiar properties of rubber materials at these temperatures.There are no static applications of rubber. The Gaussian theory of rubber elasticity demonstrates that the elastic characteristic of rubber is due to approximately 15% internal energy and the balance, 85%, is entropy change. In other words, when an elastomer is deformed, the elastomer chain network is forced to rearrange its configuration thereby storing energy through entropy change. Thermodynamically, this means that rubber elasticity is time and temperature dependent (Reference 25).The purpose of this report is to provide guidance on low temperature properties of rubber with the terminology, test methods, and mathematical models applicable to rubber, and to present some practical experience. In this way, it is hoped that mistakes can be avoided, particularly in selection of rubber materials, enabling the design engineer to weigh low-temperature material properties together with the many other factors involved in the design process.