Synchronization of the yield as a way to increase bearing capacity of frame supports

Results of testing of a yield frame support having synchronized clutches. Testing of the frames in situ and in a laboratory showed that opposite clutches yield by turn, one after another that is compliant with thermodynamics of irreversible processes. Such behavior causes blocking of the clutches, longitudinal twist of frame profile, its plastic deformation, breaking of the clutch components, asymmetrical yield of the clutches, buckling and shifting of the frames, what reduces their bearing capacity. Synchronization of the opposite clutches yielding is a key solution to provide stable operation of the frame saving and maintaining their bearing capacity. Synchronization of the opposite clutches was provided using a flexible link, for example, steel rope joining opposite clutches. New frame design proved to be much more efficient than a traditional prototype frame equipped with independent clutches. SC always demonstrated practically the same yield and synchronous paths of pliancy. Yield of SC occurred by smaller portions, average value of which was 1.962±2.29 mm, whereas corresponding elementary yield of IC extended to 6.641±6.7 mm, what increased probability of clutches blocking and destroying. Possibility of the IC jamming increases additionally because standard deviation of IC yield exceeds 100%, whereas standard deviation of SC yield in four tests was 0.43% only. Average resistance of the frame equipped with SC was 1.23 times more in comparison with IC prototype. Irreversible work of the SC resistance was 1.73 times more than corresponding work of IC. In addition, SC facilitate stable operation of the frame because variance of its resistance is 20% versus 67% for the frame having IC, and variance of the work is 10% for SC versus 50% for IC. The most important advantage is that weak but specific action of a frame equipped with SC induces strong interactions among blocking rock fragments, which produce self-supporting effect that increases stability of underground roadway.

带同步离合器（synchronized clutches）的可缩性支架支护系统的试验结果。对该支架开展的原位与实验室试验表明，对侧离合器依次先后发生屈服，这一现象符合不可逆过程热力学定律。该行为会引发离合器卡滞、支架型材纵向扭曲、塑性变形、离合器部件断裂、离合器不对称屈服、支架屈曲失稳与移位，进而降低其承载能力。实现对侧离合器屈服同步化，是保障支架稳定运行、维持其承载能力的核心解决方案。通过柔性连接件（例如连接对侧离合器的钢丝绳）可实现对侧离合器的同步化。新型支架设计相较于配备独立离合器（independent clutches）的传统原型支架，性能更为优异。同步离合器（Synchronized Clutches，简称SC）始终表现出近乎一致的屈服行为与同步柔化路径。同步离合器的单次屈服量更小，平均值为1.962±2.29 mm；而独立离合器（Independent Clutches，简称IC）的单次屈服量可达6.641±6.7 mm，这提升了离合器卡滞与损坏的概率。独立离合器的卡滞概率进一步升高，因为其屈服量的标准差超过100%；而同步离合器在4次试验中的屈服量标准差仅为0.43%。配备同步离合器的支架的平均抗力较独立离合器原型支架提升1.23倍。同步离合器的抗力不可逆功为独立离合器的1.73倍。此外，同步离合器可提升支架运行稳定性：其抗力的方差为20%，而独立离合器支架的抗力方差为67%；其功的方差为10%，而独立离合器的功的方差为50%。其最核心的优势在于：配备同步离合器的支架所产生的微弱但针对性的作用，可激发卡滞岩块间的强相互作用，形成自承载效应，提升地下巷道的稳定性。