We don't keep up-to-date lists of supported or unsupported features for implicit. What is or isn't available in implicit is best determined by assuming that it is available and trying it. Generally speaking, a feature that is not supported by implicit will trigger an error message telling you that. In the case of unsupported element formulations, LS-DYNA will generally substitute a supported element formulation for any unsupported element formulation requested by the user. In such a case, a warning message will inform the user of that substitution. For example, " *** Warning 20556 (STR+556) Tshell formulation for part ID # 1 has been switched from 1 to 2 since the stiffness matrix is not implemented for shell type: 1" Most material models are accepted by the implicit solver. If there is a material that is not accepted, LS-DYNA will terminate with an error. Having said that, not every material that is accepted for implicit analysis is ideally suited for implicit. There are different levels to which a material model may be adapted to use in implicit analysis. Most commonly used materials have undergone a rigorous development of the material "tangent stiffness" for use in implicit. For others, an approximate method of computing the tangent stiffness may be used. Data statement matimp (see note below) does not distinguish material models that have a rigorous tangent stiffess from those with an approximate tangent stiffness. Only through rigorous examination of the source code would one be able to say level of implicit implementation is used for any particular material model. Ref: Ticket#2020061810000051 ______________________________________________________________________ For foams, *MAT_083 has been improved for implicit. If you set IACC=1 and specifiy *MAT_057, internally the material is switched to *MAT_083. For hyper-elastic materials, *MAT_077 has been improved for implicit. Ref: Ticket#2019032710000024 ____________________________________________________________________ RE: Data statement matimp In the data statement matimp below, an entry of zero means that the corresponding material number is unsupported by implicit. For example, the table reveals that material types 8, 39, 86, and so on, are unsupported by the implicit solver. If the data statement matimp contains the material number instead of zero, then the corresponding material is supported for implicit calculations, but that doesn't guarantee that the material implementation for implicit is completely robust or comprehensive. Simply put, the implementation of some material models for implicit makes use of simplifying assumptions such that the tangent stiffness is approximated. When use of an unsupported material is attempted in an implicit simulation, an error message of the following format is written ... 1 5x,'*********************************************************'/ 2 5x,'* *'/ 3 5x,'* - FATAL ERROR - *'/ 4 5x,'* *'/ 5 5x,'* Material type ', i8 ,' is not supported *'/ 6 5x,'* by the implicit solver *'/ 7 5x,'* *'/ 8 5x,'*********************************************************') or in the case of *MAT_224_GYS, 1 5x,'*********************************************************'/ 2 5x,'* *'/ 3 5x,'* - FATAL ERROR - *'/ 4 5x,'* *'/ 5 5x,'* Material *MAT_224_GYS is not supported *'/ 6 5x,'* by the implicit solver *'/ 7 5x,'* *'/ 8 5x,'*********************************************************') Table of materials supported by implicit ( "data matimp" in dyn4a.F) in trunk, 28-Oct-2019: data matimp/ . 1, 2, 3, 4, 5, 6, 7, 0, 9, 10, 1 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 2 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 3 31, 32, 33, 34, 35, 36, 37, 38, 0, 40, 4 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 5 51, 52, 53, 54, 55, 0, 57, 58, 59, 60, 6 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 7 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 8 81 , 82, 83, 84, 85, 0, 87, 88, 89, 0, 9 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, . 0, 102, 103, 104, 105, 106, 107, 0, 109, 110, 1 111, 112, 0, 114, 115, 116, 117, 118, 119, 120, 2 121, 122, 123, 124, 125, 126, 127, 128, 129, 0, 3 131, 0, 133, 0, 135, 136, 137, 138, 0, 0, 4 141, 142, 143, 144, 145, 146, 0, 0, 0, 0, c 5 151, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5 151, 152, 153, 0, 0, 156, 157, 0, 159, 0, 6 161, 162, 0, 0, 165, 166, 167, 0, 169, 0, 7 0, 172, 173, 0, 175, 0, 177, 178, 179, 180, 8 181, 0, 183, 184, 185, 186, 187, 188, 189, 190, 9 0, 192, 193, 0, 195, 196, 0, 0, 199, 0, . 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 0, 0, 0, 0, 0, 216, 217, 218, 0, 0, 2 221, 0, 223, 224, 225, 226, 227, 0, 229, 0, 3 0, 232, 233, 0, 0, 0, 0, 0, 0, 240, 4 0, 242, 243, 244, 0, 0, 0, 248, 0, 0, 5 0, 0, 0, 254, 255, 0, 0, 0, 0, 260, 6 0, 0, 0, 264, 0, 266, 267, 0, 269, 270, 7 271, 0, 273, 0, 275, 0, 277, 0, 0, 0, 8 0, 0, 0, 0, 0, 286, 287, 0, 289, 0, 9 291, 0, 0, 0, 295, 296, 0, 0, 0, 0/ Table of materials supported by implicit ( "data matimp" in dyn4a.F) as it appears in the R10.0.0 source code... data matimp/ . 1, 2, 3, 4, 5, 6, 7, 0, 9, 10, 1 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 2 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 3 31, 32, 33, 34, 35, 36, 37, 38, 0, 40, 4 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 5 51, 52, 53, 54, 55, 0, 57, 58, 59, 60, 6 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 7 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 8 81 , 82, 83, 84, 85, 0, 87, 88, 89, 0, 9 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, . 0, 102, 103, 104, 105, 106, 107, 0, 109, 110, 1 111, 112, 0, 114, 115, 116, 117, 118, 119, 120, 2 121, 122, 123, 124, 125, 126, 127, 128, 129, 0, 3 131, 0, 133, 0, 135, 136, 137, 138, 0, 0, 4 141, 142, 143, 144, 145, 146, 0, 0, 0, 0, c 5 151, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5 151, 152, 153, 0, 0, 156, 157, 0, 159, 0, 6 161, 162, 0, 0, 165, 166, 167, 0, 0, 0, 7 0, 172, 173, 0, 175, 0, 177, 178, 179, 180, 8 181, 0, 183, 184, 185, 186, 0, 188, 189, 190, 9 0, 192, 193, 0, 195, 196, 0, 0, 0, 0, . 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, . 0, 0, 0, 0, 0, 216, 217, 218, 0, 0, . 221, 0, 223, 224, 225, 226, 227, 0, 229, 0, . 0, 232, 233, 0, 0, 0, 0, 0, 0, 240, . 0, 242, 243, 244, 0, 0, 0, 248, 0, 0, . 0, 0, 0, 254, 255, 0, 0, 0, 0, 0, . 0, 0, 0, 0, 0, 266, 267, 0, 269, 270, . 271, 0, 273, 0, 275, 0, 277, 0, 0, 0, . 0, 0, 0, 0, 0, 286, 287, 0, 0, 0, . 0, 0, 0, 0, 0, 0, 0, 0, 0, 0/ ________________________________________________________________ RE: Element formulations for implicit Not all element formulations are supported by the implicit solver. LS-DYNA will generally substitute a supported element formulation for any unsupported element formulation requested by the user. In such a case, a warning message will inform the user of that substitution. For example, " *** Warning 20556 (STR+556) Tshell formulation for part ID # 1 has been switched from 1 to 2 since the stiffness matrix is not implemented for shell type: 1" " *** Warning 20555 (STR+555) Shell formulation for part ID # 1 has been switched from 1 to 2 since the stiffness matrix is not implemented for shell type: 1" " *** Warning 20555 (STR+555) Shell formulation for part ID # 1 has been switched from 7 to 6 since the stiffness matrix is not implemented for shell type: 7" Ticket#2017122210000011 __________________________________________________________________ For internal (non-public) notes on implicit materials, see text file "implicit.matls".