Comprehensive Study On Heat-insulating Property And Mechanical Property Of Special Vehicle Shelter Based On Finite Element Method

The shelter is a new type of military ground equipment.With the development of military at home and abroad,the demand for various special shelters is increasing.As a general equipment and personnel loading platform,thermal design of shelter is particularly prominent,but thermal design will affect the structural and mechanical characteristics of shelter.Therefore,a scientific theoretical analysis method,which can synthesize mechanical property and heat-insulating property to guide the development and production of the shelter is urgently needed.The heat transfer coefficient is an important parameter to measure the heat-insulating property of enclosed compartments such as shelters.Firstly,in order to calculate the heat transfer coefficient of shelter,the shelter was divided into several parts.After setting the boundary conditions and solving parameters of each shelter’s model in Fluent,three-dimensional heat transfer simulation of several parts’ flat walls were carried out,the temperature distribution,heat flux distribution and heat flow of each part were obtained.The heat transfer coefficient of shelter was calculated by combining equivalent area method and the shelter’s actual heat transfer coefficient was verified by the experiment.The results show the values from simulation and experimental had good consistency.By changing the material parameters of board’s each layer,the relationship curve between each layer’s thermal conductivity and board’s heat transfer coefficient was obtained by simulation.It was concluded that thermal conductivity of the inner core has the greatest influence on shelter’s heat-insulating property;the internal structures of the board were changed and heat transfer coefficient were calculated by simulation.The structure which has less frame structure is proposed,which can effectively reduce shelter’s heat transfer coefficient.In addition,the uniformity of the frame structure has less influence on the insulation performance of shelter.Then,in order to study the mechanical property of shelter,the finite element model of the board’s structural mechanics was established.The constraints and load settings of boards’ model were set in Hyper Mesh and the static simulation analysis of the board were performed by Opti Struct.The results show the stiffness and strength of shelter reach the design requirements;the impact of the board’s internal structure on the board’s stiffness and strength were also studied,and the statics simulation analysis of the boards under each structure were carried out,the results show the impact of board’s inner frame number on boards’ stiffness and strength is complicated,but the frame structure’s uniformity has less impact on the stiffness and strength of boards.Finally,based on the previous research on heat-insulating property and mechanical property,the heat transfer coefficient,maximum displacement and maximum stress of board were set as variables.The comprehensive evaluation index was introduced and the weight coefficient was selected to comprehensively consider the mechanical property and heat-insulating property of board.Any combination of board’s each layer’s materials and board’s structures were calculated by comprehensive evaluation,the calculation results show that when board is designed into a 10-frame frame structure,the skin is made of fiber reinforced plastics,the skeleton is made of structural steel,the inner core is made of polyurethane foam and the insulation layer is made of plywood,the shelter’s overall performance reach the best.In this case,heat transfer coefficient of different insulation materials and structures can be predicted in real time,and shelter’s thermal performance can be quickly optimized in its design phase.