本篇論文內容以物理效應的設計方法為基礎,建構結合網際網路的機械設計輔助工具,可以在概念設計中,輔助建立原理性的解決方法。設計輔助工具的內容包含物理效應資料庫與輔助搜尋物理效應的程式兩大部分。網路資料庫蒐集各種物理效應的介紹,透過網路超連結的特性,提供設計者便利的設計資訊來源;搜尋程式以功能量矩陣為基礎,經由設計需求訂出的功能量,可找出選擇條件下的所有功能量變化鏈,並以中繼功能量的限制來提高搜尋工作的效率。結合物理效應資料庫與搜尋程式,可以輔助設計者找到符合設計需求的物理效應組合。另外,使用者也可透過功能量變化趨勢圖的程式,得到功能量與設計量之間關係的資訊,可有助於設計問題的解決。最後,經由投石機設計實例,比較利用物理效應輔助工具與沒有應用任何設計方法的設計成果。結果發現輔助工具可以彌補一般在概念設計中,常會出現的缺點,提供了更多樣化的設計需求解決方案,並且能快速、容易地取得設計所需的相關參考資料,以利設計者做出改良或創新的設計。 This paper illustrates a web-based mechanical design tool for finding principle solution with aid of physical effects in the stage of conceptual design. This design tool includes two main parts, a database of physical effects and a computer program for searching physical effects. The web-based database will offer designers various related design information of physical effects for application in their task. After defining the input and output functional quantities from design requirements, the search program based on “functional quantity matrix” can establish all possible chains of physical quantities in a reasonable range. The efficiency of search work can also be increased by means of adding intermediate functional quantities to restrain some unsuitable combinations. The relations between functional quantities and design quantities can be represented graphically through a program, so that the designers can solve design problems more easily. With the case of stone thrower, this design using the aided design tool will be finally compared to the design of students who have no experience on this tool. The result shows that this tool can catch up on faults of general design. With aid of this tool, different solutions and related design information can be obtained more quickly and easily.