【摘要】 为延长设施蔬菜种植周期,在连栋塑料大棚基础上通过棚室结构改进增加一层膜覆盖,设计双拱双连双膜塑料大棚,然后使用有限元软件MIDAS GEN对双拱双连双膜塑料大棚桁架结构进行三维空间建模,并对该结构在多种荷载组合工况下进行静力分析,最后测定温度性能。结果表明:双连双膜塑料大棚结构在最不利荷载工况作用下,最大应力及最大综合位移均小于规范限值,满足设计要求。与连栋塑料大棚比较,双连双膜塑料大棚12月上旬和2月下旬平均气温提高3.02℃和2.12℃,茄果类蔬菜早春提早定植10～15 d,冬季延迟采收15～25 d,耐低温茎叶类蔬菜早春提早定植30～35 d,冬季延迟到元旦采收;8月下旬降低6.76℃,夏季黄瓜和茄果类蔬菜能正常越夏。双拱双连双膜塑料大棚结构合理、整体稳定、种植周期长,为适合推广的棚室结构。更多还原

【Abstract】 In order to extend the period of growing vegetables in the plastic shed, on the basis of multi-span plastic shed, a layer of film mulching was added through the improvement of shed structure, and a double-arch double-span and double-film covered plastic shed was designed. Then the three-dimensional model of the double-arch double-span and double-film covered plastic shed were built by using the finite element software MIDAS GEN,and the static analysis of the structure was done under a variety of load combinations, and finally the temperature performance is measured. The stability analysis of the whole structure was carried out by using the finite element software MIDAS GEN, and the temperature performance was measured. The results showed that under the most unfavorable load conditions, the maximum stress and the maximum comprehensive displacement are less than the specification limits, which meets the design requirements. Compared with the multi-span plastic shed, the average air temperature in the first ten days of December and the end of February increased by 3.02 ℃ and 2.12 ℃, in early spring solanaceous vegetables was colonizated earlier by 10 to 15 days, and the harvest was delayed 15～25 days in winter. Low-temperature-tolerant stem and leaf vegetables were colonized early in spring for 30 days and delayed to New Year’s Day in winter. Lower 6.76 ℃ in late August, cucumber and solanaceous vegetables can plant normally in summer. The double-arch double-span and double-film covered plastic shed was reasonable in structure, stable in whole, long in planting period and suitable for popularization.更多还原