Abstract:

The principle of virtual work is an important part of undergraduate mechanics curriculum. Deepening the understanding of the principle is of great significance for mastering the energy principle of solid mechanics. In this paper, the expressions of virtual work principle in different courses are summarized, and some understandings of the principle are given. The main contents of this paper are as follows: (1) a qualitative description of the transition from virtual displacement principle of particle system to deformed body is given, and the relationship between virtual work of internal force and virtual strain energy is clarified; (2) The differences and correlation between the virtual work principle of rod structure and that of general elastic body are clarified, and the confusion of 

the virtual work principle of rod structure in the current textbooks is analyzed; (3) From the perspective of curriculum, the virtual work principle of particle system and deformable body is summarized, and the overall context of the principle in the curriculum is given. This paper aims to clarify the relationship of virtual work principle in each course stage and clarify some related concepts, so as to help readers form a general understanding of virtual work principle and deepen their understanding for the principle.

Key words: virtual displacement (virtual work) principle, virtual force (complementary virtual work) principle, principle of possible work, internal force virtual work, virtual strain energy