井架临界载荷与振动参数的关系

Relation between critical load and vibration parameters of derricks

根据结构形式和受力特征，将井架折算成一根沿长度上质量均匀分布、刚度恒定的简支渠，用振动理论研究井架的结构频率与作用载荷的关系。计算实例表明，井架上作用的载荷与井架结构频率的平方三线性关系。据此，可在井架载荷较小情况下，测量无载荷和有载荷下的井架结构基本频率，并通过计算公式确定井架的临界载荷。

According to its structure and load characteristics,a derrick is considered as a freely supported beam with uniform dis tributed mass and constant rigidity along the length, and the relation between the structural frequency and load on the derrick is investigated by the vibration theory. Example of calcural shows the load on the derrick is linear with square of the structural frequency of the derrick.Thereby the basic structural frequency of the derrick with of without load can be determined under the condition of miner load on the derrick, and the cirtical load of the derrick can be calculated.