In evaluating lateral behavior on the seismic and wind load, the purpose of sensitivity analysis is to find critical variables and to identify characteristic response with variability of variables. The sensitivity analysis is very important in structural diagnosis, repair and reinforcement field.
Generally, sensitivity analysis considers the probabilistic distribution of variables such as yield stress of vertical and horizontal structural members. However, in diagrid structure, the angle of diagrid braces has an immense effect on the lateral behavior by horizontal load. Therefore this study carries out using the tornado diagram method and the first-order second-moment method considering entry variables such as yield strength of steel, and damping ratio in changing angles of diagrid braces on the 12story to 60story models. And the structural analysis is performed with MIDAS GEN(Ver. 800)

The results of this study are as followings;

(1) According to linear static analysis results, the strength of diagrid braces turns out to be most sensitive factor. The damping ratio turns out to be the most important factor in linear dynamic analysis.

(2) In case of mid rise models, 12, 24 and 36story, the brace member is determined as a major variable at between 58 and 67.4 but a high rise model, under the wind load, has the brace member as a major variable at between 67.4 and 72.6

(3) As a result of comparing the tornado diagram analysis with the first-order second-moment method, the gap is very small below 2.31%. So, it is assumed that the lateral behavior of structure is linear by changing design variables. And each structural member acts independently on lateral behavior.


(4) As a result of the analysis study, location of critical sensitivity on the 12 and 24story models is distributed over middle section. The sensitivity on the 36story model is evenly distributed all sections, while it is distributed lower section on the 48 and 60story models. So, the control of the lateral displacement is very effective when the reinforcement located in maximum sensitivity area.

(5) According to limit state equation, this study suggest the limitation of target displacement to meet the serviceability target reliability index.