建築因設計工具的演進，造型日趨複雜，而建築系學生的結構知識並不足以應對過於複雜的造型。本研究希望開發一套具有圖形化介面的建築結構輔助設計程式，簡稱PAnDAS（Program for Assisting in Design of Architectural Structures）。讓非建築結構專業背景的使用者，能透過簡單的操作完成簡易結構分析。
本研究先訪談使用者，進行需求分析與程式功能規劃。依照功能，將程式分為操作介面、資料庫與工具庫三部份，並採用物件導向的方式以C#語言進行實作。
在操作介面的設計上，以引導式操作、預設參數、內建選單等方式，讓使用者能在短時間內學會軟體的操作，並快速建立結構模型與進行分析。工具庫中的運算核心以勁度矩陣法進行結構分析，並且加入樓版載重自動分配、擬剛性樓板、地震力計算等輔助分析的功能。
本研究將PAnDAS與商業結構分析軟體SAP2000進行比較，以驗證本研究程式計算的正確性與假設的合理性。以簡單的小模型檢核PAnDAS運算核心的正確性，是為基礎驗證。以多種不同的模型，檢核各輔助功能的正確性與適用範圍，包括：樓版載重分配、擬剛性樓版、地震力計算與分配。
樓版載重分配驗證中，因PAnDAS採用的固端反力公式未考慮剪力變形，故當構件承受非對稱樓版載重時，計算結果會產生些微的誤差，但仍在可接受範圍。擬剛性樓版以鉸接的剛性斜撐來模擬剛性樓版，故無法模擬樓版面內方向彎矩傳遞，使PAnDAS分析結果產生誤差，此誤差在樓版為水平時仍在可接受範圍內，但當樓版傾斜時，誤差則會變得明顯。地震力計算與分配驗證則顯示PAnDAS之輔助地震力計算與分配功能可正確運作。
本研究完成PAnDAS的架構規畫與操作介面的設計，並進行前處理器與分析核心的實作與檢討。而程式功能的擴充與後處理器的開發，則有待後續研究補足。

PAnDAS: A Simplified Building Structural Analysis Program
Ho Yen-Ting
Tu Yi-Hsuan
Department of Architecture
ABSTRACT
The purpose of this study is to develop a set of structure analysis program with a graphical user interface that allows users to easily operate and complete simple structural analysis by carrying out a simple operation even without having a professional background of the building structure.
After the users’ needs have been identified through the interviews, this study conducts requirement and program function plans based on the custom software development process, as well as uses an object-oriented approach with the C# language implementation. As for the design of the user interface, guided operation, present parameters and built-in menus are adopted, allowing users to learn software operation, establish the structural model and conduct analysis in a short time.
The core of this program is to analyze the stiffness matrix and also adds other auxiliary functions such as floors’ load distribution, quasi-rigid floor, and the calculation of seismic load. The results will be compared with the professional structure analysis software SAP2000 to verify the correctness of calculation of this program and the rationality of the assumptions. The results of the comparison show that apart from a relatively larger error in the analysis of quasi-rigid floor, the hypothesis of floors’ load distribution and seismic load calculation are indeed reliable.
Keywords: Building structure, Structure analysis, Interface design, Design Tool
INTRODUCTION
Free form has become the mainstream in architectural design recently due to the development of related technologies; nonetheless, general designers’ knowledge on structure is still insufficient to reach to a comprehensive analysis of its structure. On this account, this study attempts to develop an auxiliary design program called PAnDAS (Program for Assisting in Design of Architectural Structures) that can be operated easily for users even with limited basic knowledge and without professional training. It can reduce manual labor and time waste if designers could self-assess the feasibility of the structure design at the initial stage.
In the beginning of the study, the existing structural analysis programs which in-clude the commonly used SAP2000, PISA3D developed by IDEERS, the plug Karam-ba under Rihno/Grasshopper, and the rough estimating program of the sizes of columns exploited by National Cheng Kung University have been thoroughly reviewed as the reference for the development of the interface design, programming architecture and calculation methods of PAnDAS. Further, based on the development process of this study, interviews of users have been conducted in order to have a better understanding of users’ needs and to perform requirements analysis. In addition, the MVC architecture has been referred for the overall planning of the program system of PanDAS, and the structure is shown as in Fig. 1.

Fig. 2 PAnDAS’ program architecture
User Interface Development
Referring to the existing structure analysis software and structure analysis process, the interface of PAnDAS has divided the windows into several areas, including the function area, operation area, display area and data table area based on respective uses as shown in Fig. 2. . Moreover, several auxiliary functions such as operation recheck, function lock, default parameters and quick building of model have been added as well, allowing users to quickly become familiar with the operation of the system.

Fig. 2 PAnDAS’s UI
Analysis Core and Verification
The analysis core of PAnDAS uses the structure matrix method and adds some other auxiliary analysis functions such as the floors’ load distribution, quasi-rigid floor and seismic load calculation. In order to be able to test the correctness of calculation and the applicability of auxiliary functions, this study establishes several analyzing models of different types to compare with the calculated results obtained by commercial software. The comparison includes joint displacement, endpoint reaction and the internal force of elements.
There are two types of verification, simple verification and functional verification. Simple verification examines the correctness of PAnDAS analysis core with a small model, while functional verification uses different models to check the reliability of auxiliary analysis functions.
In verification of the floors ’ load distribution, due to that the shear deformation is not considered in the formula of fixed-end force, the calculated result might have slight error. Furthermore, in comparison of the calculated result of quasi-rigid floor and rigid floor model, there are differenences in the the analysis results due to the differ-enent ways of the energy transfer. When the floor keeps its horizontal position, the dif-ference would still be in an acceptable range; however, when the floor starts to tilt, it would produce significant errors and make the model inaccurate.
During the verification of seismic load calculation and loads separation, the floor would be assumed as rigid when SAP2000 needs to simulate the accidental torsion of the mass. However, as PAnDAS does not have this function, it needs to calculate the the seismic loads of joints and then uses SAP2000 to compare the analysis results. The results of the comparison show that the calculation of seismic load of PAnDAS is relia-ble.
CONCLUSION
In conclusion, so far on the operating functions, PAnDAS can establish and ana-lyze the structural model, but it is not yet able to show the graphical results, nor to ex-amine the design of structure elements and the design optimization. In addition, the user interface can only be operated through the menu or buttons, which needs a further re-search to compensate for the lack of programming technologies. Moreover, on the ana-lyzing functions, PAnDAS can only run liner static analysis for now, which means that the range of application the analyzed model has been limited. Therefore, it is hoped that this study can be used as a reference for future researchers to conduct a further explora-tion on the areas of material properties, structure types and analysis methods to strengthen the functionality of PAnDAS and to extend the range of its uses.

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