摘要:
采用有限元软件LS-DYNA中的SPH 算法实现聚能装药射流形成过程的三维数值模拟。将SPH
方法和FEM 方法与理论计算结果相比较。研究结果表明:SPH 数值模拟计算过程十分稳定,避免了有限元
数值模拟过程中的网格扭曲、缠绕和物质穿透等问题,而且计算精度比有限元方法更高;采用SPH 方法计算
的射流速度、射流长度与有限元计算结果和理论计算结果的误差均小于5%,因此该方法对于模拟诸如聚能
装药等多介质、大变形问题十分有效;初始相邻粒子数N 的最佳取值范围为600~1800,在该范围内计算结
果的误差小于3%,且计算效率高。
Abstract:
Basedonthesmoothedparticlehydrodynamics(SPH)methodinLS-DYNAsoftware,the
shapedchargejetprocesswassimulated.Andthemechanismoftheshapedchargejetwasdiscussed
accordingtothenumericalsimulationresults.Toanalyzetheaccuracy,effectivenessandsuperiority
aboutthismethod,aswellastheerrorbroughtbydifferentinitialnumbersN oftouchingneighbors
perparticle,thenumericalsimulationresultswerecomparedwithtwo-dimensional(2D)finiteelementresultsandtheoreticalcalculations.
Theinvestigatedresultsshowthatsomeproblems,suchas
griddistortion,windingandcontactpenetrationwhichoftenhappeninthefiniteelementmethod,can
beavoidedintheSPH method,sothecalculationprocessbytheSPH methodisstable,andthecalculationprecisionishigherthanthatbythe2Dfiniteelementmethod.
Therelativeerrorofthejettip
velocityandthejetlengthcalculatedbytheSPH methodcomparedwiththefiniteelementresultsand
theoreticalcalculationsarebothlowerthanfivepercent,thereforetheSPH methodisadaptablein
multi-material,largedeformationproblemssuchasshapedcharges.ThemostidealNisfrom600to
1800,inwhichtherelativeerrorislowerthan3%andthecomputationalefficiencyishigh.
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