冷轧带肋钢筋应力松弛试验机的研制

Development of cold rolled ribbed steel bar stress relaxation testing machine

针对冷轧带肋钢筋材料在高应力(高于松弛下限)作用下会产生流变(晶格变形、滑移),应力将随时间衰减的特性,研制该电子应力松弛试验机。该机采用MaxTest标准化模块软件系统进行应力、变形和位移闭环的自动控制,同时在结构设计上通过使用三爪夹具保证防滑,通过结构力学的核算来保证其刚度,从而具有防止试样打滑、精确地负荷和形变控制、连续并适时地绘制松驰力-试验时间曲线的特点,并设计在意外因素(停电、断电)下继续进行试验的措施,充分满足标准要求和实际工作需要。

For cold rolled ribbed steel bar material in high stress （higher than the relaxation limit） generates rheological （lattice deformation, slip） behavior and the stress decays with the time, the authors designed the electronic stress relaxation testing machine. The machine adopts MaxTest standard module software system to automatically control the closed-loop of stress, deformation and displacement. At the same time, used to prevent slipping and structural mechanics in the machine design three-claw clamp was calculation was carried out to guarantee its stiffness. Thus the machine can prevent the sample from slipping, load accurately and control deformation, draw relaxation test time curve continuously and timely. And the measures were also designed to continue the test in the accidental factors （such as blackouts, power off and so on）. The experimental results indicated the machine can fully meet the standard requirements and actual needs.