FEMFAT-材料编写要求2页

1、 femfat 材料生成需要检测指标一、对疲劳分析软件有关材料生成的翻译内容 FAQ: What does material generation look like in FEMFAT? 问: 在FEMFAT中,材料生成器是怎么工作的?Only two items of basic information are required: the material group and the ultimate tensile strength of the material. It is possible to choose from 12 material groups in the mater

2、ial generator (10 iron and 2 aluminum material groups; see FKM guideline).The material generator is based by default on the FKM guideline and generates material data for a survival probability of 97.5% for a specimen diameter of 7.5 mm.仅有两项基本信息是必需的:材料类型和材料的极限抗拉强度. 可以从材料生成器中选择类型(10种钢铁和2种铝材分类,参见 FKM指南

3、). 材料生成器基于FKM 指南(德国关于分析强度的标准)，生成试棒直径为7.5mm存活率97.5%的材料数据。After selection of the material group, the complete material dataset can be generated by entering the ultimate tensile strength. An analysis can now be performed using such a dataset. It must be mentioned, however, that when using these materia

4、l data, conservative results can be expected. The following data are advantageous in order to increase the precision:选择好材料类型（球墨铸铁nodual cast iron）后，通过输入极限抗拉强度能够生成完整地材料数据，并进行零部件分析。不过，必须提及的是，使用这些数据，只能获得比较保守的结果（精度差）。为了提高精度，下列数据的输入是很有优势的： Tension/compression alternating strength TA 拉/压交变循环疲劳强度 Tension/c

5、ompression pulsating strength TP (defined as upper stress in FEMFAT) 拉/压脉冲循环疲劳强度 Bending fatigue strength BA 弯曲疲劳强度This makes it possible to find the mean stress sensitivity of the material using the relationship 通过下式可以找到平均应力的敏感度 M =2* TA / TP - 1.Furthermore, the support effect is defined by the ra

6、tio V= BA / TA (important for analyses with gradient influence in FEMFAT). The following steps apply if only one of the values mentioned is known:甚至，通过V（v=BA / TA）值定义支撑效应（在FEMFAT软件中对梯度影响分析很重要的参数）. 即便知道一个参数，下列数据也可获得：1.) Determination of the values V and M of the base material. （基本材料的V 、M 的确定）2.) Modi

7、fication of all values on the basis of, e.g., the known tension /compression alternating strength: TA. 根材料的基本数据比如拉压交变疲劳强度 TA.例子：Example:Material group, general structural carbon steels, UTS = 500 N/mm2（抗拉强度）, Yield = 300 N/mm2（屈服强度） TA = 250N/mm2 （拉压疲劳极限） . Step1: Selecting the material groupand ent

8、ering UTS leads to the result in figure 1. 第一步：选择材料类型，普通结构碳素钢，UTS = 500 N/mm2, Yield = 300 N/mm2, TA = 250N/mm2图1Step2: Modification of the yield strength (300 instead of the suggested 284.5 and alternating strength (the material generator modifiesBAin the correct ratio depending on the selected mat

9、erial group). We calculate the mean stress sensitivity as M=2*(225/418.6)-1=0.075.Consequently, the finished material dataset looks as follows:Replacement in the formula for mean stress sensitivity using the values M = 0.075 and the known alternating strength of 250N/mm2 ，gives the new pulsating strength of 465.1 N/mm2.第二步： 修改屈服强度值（建议的284.5改成300，交变强度（拉压疲劳极限修正为250，则弯曲疲劳为276.7，扭转剪切疲劳为144.3）。同时根据未修改前的平均应力敏感系数与修改后敏感系数相等的原则，确定脉冲强度。图2 未修改前的M值： M=2*(225/418.6)-1=0.075，拉压疲劳极限修改后，冲击强度变为：2*250/（1