An Efficient Structural Analysis of Super Tall Mega Frame Buildings Using a Multi-level Condensation Method

Abstract

The mega frame system is considered to be suitable for skyscrapers, because it offers the structural efficiency of providing high rigidity against lateral loads, with a minimum amount of structural materials. Since the super tall mega frame building has a large number of elements and nodes, dynamic analyses of this system require significant computational resources. Therefore, a matrix condensation technique can be employed to efficiently predict the structural behavior of a mega frame structure. However, the computational resources required for the matrix condensation process of a super tall mega frame structure by a conventional condensation technique are significant, because hundreds of thousands of degrees of freedoms (DOFs) should be condensed. To overcome this difficulty, the purpose of this study is set as the development of an efficient matrix condensation method with accuracy for a mega frame structure. Mega elements, sub-mega elements and multi-level condensation techniques are developed for saving the computing resources required for matrix condensation. A special purpose computer program for the analysis of mega frame structures has been developed, and structural analyses of a 100-story mega frame structure were performed to verify the effectiveness of the proposed method. Based on the analysis results, it was confirmed that the proposed method could provide an efficient analytical model with outstanding accuracy, requiring significantly reduced computational efforts for both matrix condensation and structural analysis. Therefore, the developed computer program is expected to provide an efficient means for the preliminary design of mega frame structures.