Abstract: Tacit knowledge and its spread are important foundations that constitute the core competitiveness of modern enterprises. Tacit knowledge cannot be explained by language. They can only be demonstrated to prove that it is an existing knowledge. The way to learn tacit knowledge is to comprehend and practice. The existing researches on the transmission of tacit knowledge mainly focus on qualitative research, and the number of the quantitative research is less. On the other hand, in the existing tacit knowledge simulation model, there is less discussion about the forgetting mechanism in tacit knowledge dissemination. The SIR model used in the epidemiological model of this study is suitable for simulating the propagation of tacit knowledge within a company. Firstly, the SIR model of a complex network of corporate tacit knowledge dissemination, which includes infected, susceptible, and removed persons, is considered. Secondly, the steady-state analysis of the model is used to calculate the propagation rate threshold of tacit knowledge dissemination in the enterprise which is λ_c. When the rate of tacit knowledge transmission is λ>λ_c, the tacit knowledge investigated can be disseminated within the enterprise, otherwise,the tacit knowledge investigated will gradually disappear within the company. Again, the Runge-Kuntt method is used to solve the above differential equations, and the impact of model parameters on the propagation of tacit knowledge is analyzed. Finally, Matlab is applied to numerical simulation of model parameters. It's found that:the propagation of tacit knowledge within the company is affected by the factors of forgetting and the network structure. Under the condition that the network structure is determined, the greater the rate of oblivion is, the slower the dissemination of tacit knowledge within the company is, or even disappears. In order to improve the effect of tacit knowledge dissemination, companies should regularly conduct intervention training to reduce the impact of forgetting mechanisms on the spread of tacit knowledge. This model has reference value for strengthening the enterprise knowledge management, cultural heritage, education and learning, rumors dissemination, and dissemination of public opinion to develop effective market strategies.

Key words: tacit knowledge, complex networks, knowledge propagation, forgetting mechanism, epidemic model