M.F.Ghanameh
,
D.Thevenet
,
A.Zeghloul
材料科学技术（英）
The stress concentrations in offshore structures usually occur at the intersections of tubular members. For some joints, the stress concentration can produce a maximum stress at the intersection as high as thirty times the nominal stress acting in the members. Stress concentrations aggravate the fatigue of tubular joints in many existing offshore structures. For this reason, accurate computation of stress concentration is very important in tubular joints design. A new study of tubular joints was presented. They were subjected to Combined loading (Com): Axial (Ax) and rotational bending “combined bending (CB)” loading since a lot of studies already done for the joints subjected to one or two of the three types of loading applied to the tubular joints: “in-plane bending (IPB), out-of-plane bending (OPB) and Ax loading”.
关键词:
Stress concentration
,
null
,
null
,
null
熊勇
,
陈昌达
,
谢向宇
,
方明伟
,
陈岩
宇航材料工艺
doi:10.12044/j.issn.1007-2330.2017.03.016
某导弹发射架在进行第3次动载荷试验过程时,其上的一件42CrMo外六角高强度螺栓出现了断裂;通过对断口进行宏微观检查、电镜观察、金相组织检查、硬度检查及化学成分分析,确定了零件的断裂性质和断裂原因.结果表明:螺栓的断裂性质为原始裂纹引起的应力腐蚀断裂.由于螺栓在镀锌前存在原始微裂纹,造成了应力集中,并在随后的镀锌过程中出现了腐蚀现象;在试验过程中,由于弯曲应力和大气环境中氧、硫、氯、钠等腐蚀介质的共同作用,导致了螺栓的断裂.另外零件硬度值偏高,存在轻微的回火脆性,对断裂也有一定的影响.
关键词:
外六角螺栓
,
应力腐蚀
,
应力集中
,
回火脆性
