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To improve the transmission efficiency and reduce the damage to pipes in the hydraulic systems of tunnel boring machine subjected to random vibration, this paper aims to propose a novel dynamic characteristic analysis method that considers random vibration.

A fluid-structure interaction motion equation of the pipe is established by using Hamilton’s principle. The finite element method and discrete analysis method of random vibration are used to construct a model of the dynamic behavior of the pipe.

The influences of fluid parameters and external excitation parameters on the dynamic characteristics of pipes are analyzed. The experimental results are found to be in good agreement with the simulation results, which demonstrates that the proposed analytical method can provide a theoretical reference for the design and selection of hydraulic pipes subjected to random vibration.

The proposed method can be regarded as a future calculation method for pipes subjected to random vibration, and the transmission efficiency of the pipe can be improved.

Based on the idea of part standardisation and product differentiation in lean management, this paper answers the question when integrate firms should choose market foreclosure to maximise profits by studying a two-tier supply chain, which contains three types of firms: suppliers, manufacturers and integrated firms. Moreover, the effect of the substitutability between final products and the competition among firms in the supply chain would be investigated from the perspective of dynamic analysis.

Considering the decision order of integrated firms and manufacturers in the downstream of the supply chain, the authors build three competition models. In each model, integrated firms compete with manufacturers in Bertrand–Nash fashion. And, suppliers compete with each other in Cournot fashion, so do integrated firms and manufacturers. The authors further discuss how the competitive relationship between firms affect the equilibrium result.

Numerical analysis reveals that under other conditions unchanged, the increased competition between downstream firms leads to the rise in the willingness of selling parts for integrated firms, while the increase in the number of suppliers has the opposite effect. In addition, due to the market change before and after the vertical merger, it may lead to the transition from profitable to unprofitable for the vertical merger.

This paper provides a theoretical analysis and managerial implication for integrated firms' market foreclosure decision. From the perspective of dynamic analysis, this paper demonstrates the result of vertical mergers and provides an explanation for the failure of vertical mergers.