With people's increasing concern about food safety, cold-chain logistics distribution centre is playing an important role in preventing food from going bad. Now cold-chain logistics distribution centres have the problems of too much transportation, low degree of automation, unreasonable layout planning, complex distribution process etc. It is important to solve these problems in order to achieve efficient distribution. Firstly the modeling and simulation for the operation process of a fruits and vegetables cold-chain logistics distribution centre by using Flexsim software is realized. Then the paper analyses the preliminary output data and finds out the bottleneck and idle resources. Finally this paper makes adjustments for the system to get a better result which hopes to give a reference for the modeling and simulation for the operation process of other cold-chain logistics distribution centres.

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A B S T R A C T In the present paper, the interfacial crack growth of fibre reinforced composites under tension-tension cyclic load was simulated through the secondary development of the commercial finite element package ANSYS. For the importance of frictional degradation on the debonded interface during fatigue process, the modified power degradation model proposed in the authors' previous work is introduced into the present finite element analysis. Energy release rates rather than stress intensity factors are calculated in terms of difference approximation and utilized in Paris formula. Both looping cyclic load, calculating energy release rate, defining debond criterion and crack propagation law; updating parameters are programmed in ANSYS parametric design language, and the relationships between the parameters (such as the damage factor) and the number of cycles are obtained; the non-uniform stiffness degradation of matrix is taken into account. The numerical results are compared and discussed with the analytical solutions and good agreement is found. At the same time, a comparison between the present investigation and an experiment study is addressed.The interfacial properties of fibre reinforced composites (FRCs) play an important role in determining the lifetime and durability of engineering structures and mechanical systems. For this reason, the interfacial behaviour has been studied over several decades, and two typical models have been widely used in analyses, i.e. Gao-Mai-Cotterell model 1 and Hsueh's model. 2,3 The Gao-Mai-Cotterell model predicts the trend of maximum debond stress effectively for long-embedded fibre; in contrast, the Hsueh's model gives a good prediction of maximum debond stress for short-embedded fibre. 4 As the interfacial behaviour of FRCs under cyclic load is quite different to that under monotonic load, 5,6 some investigations focusing on interfacial fatigue properties were carried out in recent years. 7-10 Numerical methods are effective tools and have been widely used in composite interface analyses. By the use of a three-dimensional (3D) finite element (FE) model, Schüller validated the analytical approach for the interfacial transverse stress and calculated the energy release Correspondance: Zhifei Shi.

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