Ansys Workbench Ansys Workbench Vinduff (Structural) (OP) 18 Jun 18 21:30 Hello! I read from ansys element reference that for solid 65 the key option (1) is used to include or suppress extra deformation shapes. I would like to know what extra deformation shape mean. RE: Ansys Workbench 2 NRP99 (Mechanical) 19 Jun 18 04:18 Here is your answer-thread569-409767: ANSYS APDL Solid45 KEYOPT(1) = 0, What is the logical meaning of Include extra displacement shapes? Make sure you check the link at the end which provides very good information on shear locking and Volumetric locking in context of elements options. Also note that mathematically, extra shape functions are added when KEYOPT(1) = 0 is set(include extra displacement shapes). Check this Link and this Link Also SOLID65 is legacy element which is discontinued. It is recommended to use the current-technology element SOLID185. RE: Ansys Workbench Vinduff (Structural) (OP) 19 Jun 18 09:27 Thank you NRP99 for your answer I tried to use SOLID185, but I didn't find how to input the tensile and compressive strength of concrete. I am doing a simulation for rc frame, when I suppress extra deformation ansys gives me close results to experimental ones, but when I input KEYOPT(1)= 0 (include extra deformation shapes) the results drifting away from experimental. My question is how can I know if I need extra displacement shape or not? RE: Ansys Workbench NRP99 (Mechanical) 19 Jun 18 15:56 I have not worked with concrete material model. Perhaps you should check your mesh density for difference in results. Also I think KEYOPT(1) = 0 is used when you have high distortion or bending of elements. This option will alleviate the shear locking by introducing extra shape functions. This is what I understand from the above links. Check this Link for more information on concrete modelling.