COMPL13-Impact.pptVIP

Modeling Techniques 治叮赖业驻岁揉徒购伞杉打滁荫潮都蔽硝瘟秦夸兑钙滁邀蜡风泪拷丈浸淀COMP-L13-ImpactCOMP-L13-Impact Modeling Techniques Stable time increment For Abaqus/Explicit, the concept of the stable time increment is important to understand When modeling composites at the laminate level, very small element dimensions can be encountered This can lead to a very small stable time increment, requiring a large number of increments to complete an analysis For a typical composite where Le=0.2 mm, r =1.5e-9, E=65 GPa,and n =0.3, Dt is on the order of 1e-10 seconds. To simulate 1 millisecond will require 10 million increments! Some ideas for dealing with this follow. 遗苇羽鹏甩洒抵枢吁杯微椿勃乃蜡浩橇薯声昌姥颅迪祈珊攀筑瘪煌察僵糜COMP-L13-ImpactCOMP-L13-Impact Modeling Techniques Stable time increment Use double precision if the number of increments will exceed 300,000 To attempt a more time economical solution, the following may be helpful Mass scaling can be used to speed up the simulation for the purposes of checking model setup Dynamic response will be affected Group layers of common material orientation together and model as one layer Use continuum macroscopic (i.e., anisotropic global) properties to model the composite instead of using a mixed modeling technique 械疥责柄靴谭讫吨赔协褥霖混虐液士摈荐堕造棺洒豁唤较很宦轧乡锚俭吃COMP-L13-ImpactCOMP-L13-Impact Modeling Techniques Interior surfaces for erosion If erosion will be considered in an impact analysis, care must be taken when defining contact Interior mesh surfaces must be included in the contact definitions The inclusion of interior faces is not currently supported in Abaqus/CAE, and requires a manual edit to the input file. For example: *SURFACE, NAME=interior_elems, TYPE=ELEMENTall_elems, interior This creates a surface named interior_elems consisting of the interior faces of the element set all_elems, which can now be used in the contact domain 颗杠矢篱稀婴费嘉亩涯阿边翱慈混寐莽聂沁扫澄鸭麦谢窿签便拍居瓤谍谬COMP-L13-ImpactCOMP-L13-Impact With the increasing use of composite materials in automobiles and aircraft, the a