简介：Thisletterpresentsatheoreticalmodelofthenormal(head-on)collisionsbetweentwosoftspheresforpredictingtheexperimentalcharacteristicofthecoefficientofrestitutiondependentonimpactvelocity.Afterthecontactforcelawbetweenthecontactedspheresduringacollisionisphenomenologicallyformulatedintermsofthecompressionoroverlapdisplacementunderconsiderationofanelastic-plasticloadingandaplasticunloadingsubprocesses,thecoefficientofrestitutionisgainedbythedynamicequationofthecontactprocessonceaninitialimpactvelocityisinput.Itisfoundthatthetheoreticalpredictionsofthecoefficientofrestitutionvaryingwiththeimpactvelocityarewellinagreementwiththeexistingexperimentalcharacteristicswhicharefittedbytheexplicitformula.