The loss factors and their effects on the magnitude and frequency of resonance peaks in various mechanical sys-tems are reviewed for acoustic,vibration,and vibration fatigue applications.The main trends and relationsh...The loss factors and their effects on the magnitude and frequency of resonance peaks in various mechanical sys-tems are reviewed for acoustic,vibration,and vibration fatigue applications.The main trends and relationships were obtained for linear mechanical models with hysteresis damping.The well-known features(complex module of elasticity,total loss factor,etc.)are clarified for practical engineers and students,and new results are presented(in particular,for 2-DOF in-series models with hysteresis friction).The results are of both educational and prac-tical interest and may be applied for NVH analysis and testing,mechanical and aeromechanical design,and noise and vibration control in buildings.展开更多
One of gurus in the field of acoustics and vibration was Leo Beranek,an engineer and scientist born in the family of a farmer who came to USA from Bohemia(now a part of the Czech Republic).Several generations of vibro...One of gurus in the field of acoustics and vibration was Leo Beranek,an engineer and scientist born in the family of a farmer who came to USA from Bohemia(now a part of the Czech Republic).Several generations of vibroacoustic engineers studied a lot from his books and utilized the measurement techniques invented and implemented by him.展开更多
1 Introduction Non-lethal weapons are mainly used to disperse illegal demonstrations and street riots without inflicting serious physical injuries on the law violators.The development of non-lethal weapons complies wi...1 Introduction Non-lethal weapons are mainly used to disperse illegal demonstrations and street riots without inflicting serious physical injuries on the law violators.The development of non-lethal weapons complies with the civilized standards aimed to protect the law-abiding population from violent crowds with no casualties and injuries.It is noteworthy that tasers and pepper sprays are already in widespread use for personal self-defense.Thunder and lightning are the simplest natural examples of non-lethal and lethal weapon.Thunders sound frightening but they do not kill,lightnings can kill.展开更多
文摘The loss factors and their effects on the magnitude and frequency of resonance peaks in various mechanical sys-tems are reviewed for acoustic,vibration,and vibration fatigue applications.The main trends and relationships were obtained for linear mechanical models with hysteresis damping.The well-known features(complex module of elasticity,total loss factor,etc.)are clarified for practical engineers and students,and new results are presented(in particular,for 2-DOF in-series models with hysteresis friction).The results are of both educational and prac-tical interest and may be applied for NVH analysis and testing,mechanical and aeromechanical design,and noise and vibration control in buildings.
文摘One of gurus in the field of acoustics and vibration was Leo Beranek,an engineer and scientist born in the family of a farmer who came to USA from Bohemia(now a part of the Czech Republic).Several generations of vibroacoustic engineers studied a lot from his books and utilized the measurement techniques invented and implemented by him.
文摘1 Introduction Non-lethal weapons are mainly used to disperse illegal demonstrations and street riots without inflicting serious physical injuries on the law violators.The development of non-lethal weapons complies with the civilized standards aimed to protect the law-abiding population from violent crowds with no casualties and injuries.It is noteworthy that tasers and pepper sprays are already in widespread use for personal self-defense.Thunder and lightning are the simplest natural examples of non-lethal and lethal weapon.Thunders sound frightening but they do not kill,lightnings can kill.
