Study On Mechanical Properties And Crack Detection Of Eggs

In the production of salted duck eggs and preserved eggs,removing cracked eggs is a key step in the whole process.In the damage detection of the eggshell,the existing equipment detects the cracked egg through the sound signal.However,the detection result of the sound signal is relatively single,which can not accurately judge the specific geometric characteristics of the crack.In order to break through the application limitations of sound signal detection,this paper uses machine vision to compile Freeman chain code for crack pictures on eggshell.According to the mechanical analysis results of eggshell,the specific causes of crack formation are found out,which provides theoretical basis for egg processing technology and safe transportation guidance scheme.The composition of the egg is analyzed firstly in this thesis.By simplifying the egg shell into a quadric shell without torque,the mechanical model of the egg shell is established by using the elastic thin shell theory.The distribution characteristics of the overall stress value on the egg shell under the concentrated load are analyzed,which provides a theoretical basis for the causes of cracks.Then,an experimental device was designed and built.Through the device,the specific images of eggshell cracks under different impact forces and the relationship between the corresponding impact forces were obtained,and the relationship between the geometric characteristics of eggshell cracks and the impact forces was summarized.Secondly,by comparing the geometric characteristics of crack and its impact stress state,the stress state of eggshell corresponding to different geometric characteristics of crack is determined,which provides a theoretical basis for machine vision analysis of the mechanical principle of crack formation.Finally,the experimental platform of egg damage detection is built.Through the pre-processing of machine vision noise reduction and the post-processing of Freeman chain code,the crack length characteristics are unified with the mechanical model established in this paper,and the whole process from the geometric characteristics of crack to the analysis of the cause of crack formation is completed,which verifies the correctness of the research theory and method in this paper.In this paper,a method of using machine vision technology and Freeman chain code to code the crack image is proposed.The final analysis results can provide suggestions for the improvement and optimization of the transportation,packaging and other processes in the processing and production of egg products.