摘要
由于膜片在工作过程中经历高频率的振动,因而疲劳断裂是其主要失效形式.为提高膜片的疲劳寿命,文中通过有限元方法对汽车无触点电子喇叭膜片进行了数值模态分析,并通过实验方法深入研究了膜片断裂失效的机理.结果表明:汽车喇叭膜片在各阶模态下的等效应力最大值均发生在膜片上底面的外缘附近,因此该区域将是膜片最容易疲劳屈服而发生疲劳断裂的区域.由于各膜片间存在一定的尺寸误差和装配误差,使得各膜片的固有频率存在较大的差异,因此,在相同的激励频率下表现为不同的振动特性.喇叭膜片疲劳断裂时的裂纹在等效应力最大值附近萌生,因此为增大喇叭膜片的疲劳寿命,在膜片设计时应设法减小膜片上底面外缘处的应力集中.
Fatigue fracture is the main failure form of the diaphragm because it undergoes the high-frequency vibration in the process of work. In order to prolong the fatigue life of the diaphragm, numerical modal analysis of the diaphragm for a non-contact electronic horn of automobiles is carried out based on the finite element method （FEM）, and the mechanism of fracture failure is studied by experiment. The results show that the maximum value of equivalent stress of every order mode arose near the outer edge of the upper base of the diaphragm, in which the diaphragm is subjected to the fatigue yield as well as the fatigue fracture most easily. The natural frequencies among the diaphragms are different greatly because there are certain size errors and assembling errors （such as assembling clearance and preload level） among them. Therefore, the diaphragms represent different natural frequencies at the same excitation frequency. The crack initiates in the vicinity of the maximum value of equivalent stress when fatigue crack occurs in the horn diaphragm. Therefore, some measures should be taken to lessen the stress concentration near the outer edge of the upper base of the diaphragm so as to prolong the life cycle of the horn diaphragm.
出处
《应用科技》
CAS
2012年第6期39-44,共6页
Applied Science and Technology
基金
黑龙江省博士后基金资助项目(3236301278)
关键词
无触点电子
喇叭
膜片
断裂
失效机理
模态分析
疲劳寿命
non-contact electronic
thorn
diaphragm
fracture failure mecharism
modal analysis
fatigue life
