T he contact FEM analysis was carried out with three types of rebar diameter ( 16,25,32) and three types of thread pitch for each rebar diameter,and deformation,stress of screw tooth cusp and contact stress distribution were researched in detail. Results show that with designed mechanical connection length and different thread pitch,static performance of all the rebar mechanical connection assembles meets the deformation and strength requirements of code. T he proposed thread pitches of rebar with diameters of 16,25 and 32 are 2. 0,2. 5,3. 0 mm based on comprehensive consideration of stress uniformity,geometry dimension of rebar,process difficulty and feasibility. W ith the stretching load,contact pairs are closed at one side and separated at other side. T he maximum amount of separation existed at the first thread and last thread. Stresses of middle threads decreased rapidly and tend to uniformity except larger stresses of the first and last thread sharp angle. U niformity of thread load transference become better with more threads ( smaller thread pitch) ,but process becomes more difficult. Stress level of thread sharp angle is related to rebar diameter and thread pitch. T he maximum contact stress is located at thread sharp angle,decreases rapidly to the direction of thread mean diameter and tend to uniformity,it means that the load transferring part of thread is mainly mean diameter range.%选取3种典型直径(16，25，32)的钢筋，每种钢筋选取3种螺距，开展了钢筋直螺纹连接组件接触有限元分析，系统地研究了直螺纹连接接头组件的变形、螺牙尖角应力及接触应力分布特征。结果表明：在设计连接接头长度下，采用不同的螺距时，连接接头组件的静力受力性能均满足钢筋连接的强度及变形要求，但考虑到受力的均匀性、钢筋几何尺寸特点、加工难易程度及可行性，建议16，25，32钢筋机械连接采用的螺距分别为2.0，2.5，3.0 mm；拉伸荷载作用下，螺牙接触对均在一侧密贴，另一侧分离，螺牙接触面分离量在首尾螺牙处最大；除首尾螺牙的尖角应力较大外，其余螺牙的应力迅速降低并较为均匀，即螺牙数目越多(螺距越小)，螺牙承受荷载的均匀程度越好，但加工越困难；连接组件的螺牙尖角应力与钢筋直径、螺距大小有关；螺牙接触对的接触点最大应力在螺牙的尖角处，而向螺纹中径则迅速衰减并稳定，即螺纹连接组件的牙体荷载传递区域主要在中径附近。
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