The present invention discloses a bidirectional collapse-proof damper with a macroscopic NPR structure and a bridge structure having the same, comprising a sleeve and a sliding rod; by adding a structure of a reducing part and a limiting body, a sliding gap exists between both ends of the limiting body and both inner ends of the reducing part; the rod body is connected with the inner side wall of the sleeve through an elastic element; the limiting body and the rod body can realize bidirectional slip in the sleeve, which have multi-level seismic performance.

A crankshaft arrangement for an internal combustion engine includes a crankshaft, a torsional vibration damper having a primary mass and a flywheel, wherein the primary mass is connected fixedly to the crankshaft, and the flywheel and the primary mass are coupled via a viscous fluid. The torsional vibration damper is attached to an output end of the crankshaft. The primary mass is coupled to a secondary coupling via an elastomer coupling ring. The torsional vibration damper is coupled to the secondary coupling via a feedback device. The feedback device has a negative stiffness.

A body weight adjustment mechanism for automatic adjustment to a balanced point is provided to improve vibration absorption characteristics and impact absorption characteristics. A torsion angle of a lower frame-side torsion bar when an upper frame is at a balanced point is found in advance, a torsion angle of the lower frame-side torsion bar in a state in which a person is seated is detected, the detected torsion angle is compared with the aforesaid balanced point torsion angle, a control signal is sent to an elastic force adjusting unit, and torsion angles of upper frame-side torsion bars are adjusted so that the torsion angle of the lower frame-side torsion bar becomes equal to the balanced point torsion angle. The upper frame can be set to an appropriate position in an initial state and a static state in which a person is seated and vibration and impact absorption characteristics are improved.

A suspension apparatus includes a spring piston and a spring tube body. The spring piston is slidably disposed within the spring tube body to move within the spring tube body over a travel along an axis of reciprocation. The spring piston bounds a primary positive gas spring chamber at least a first portion of a primary negative gas spring chamber. The suspension apparatus also includes a secondary negative gas spring chamber and a separator. The separator permits fluid pressure communication between the primary negative gas spring chamber and the secondary negative gas spring chamber over a first portion of the travel of the spring piston, and the separator prevents fluid pressure communication between the primary negative gas spring chamber and the secondary negative gas spring chamber over a second portion of the travel of the spring piston.

A vibration damping actuator provided by the present disclosure uses a magnet system or a spring system to introduce controllable negative stiffness characteristics into a semi-active system, so as to couple a controllable negative stiffness actuator on the basis of the semi-active actuator (controllable damping actuator). Based on the coupling and integration of the semi-active actuator (controllable damping actuator) and the controllable negative stiffness actuator, the vibration damping actuator may realize four-quadrant mechanical characteristics of an active actuator, improve the vibration damping effect of the semi-active system on the basis of ensuring the advantages of low power consumption, low cost, stability and reliability, and simple structure of the vibration control system of the semi-active actuator (controllable damping actuator), and improve the vibration isolation effect of the semi-active system to a level close to that of an active system.

A negative stiffness generating mechanism and a quasi-zero stiffness vibration isolator are provided. A housing is mounted on a base, and the axial relative positions of the housing and the base can be adjusted; a negative stiffness unit comprises inner-ring magnets, outer-ring magnets and a supporting shaft, the supporting shaft axially slides on the base and passes through the housing, the inner-ring magnets fixedly sleeve the supporting shaft, and the outer-ring magnets sleeve outside the inner-ring magnets and are divided into upper and lower groups of outer-ring magnets; the upper and lower groups of outer-ring magnets can synchronously move through a negative stiffness adjusting device; and the axial relative positions of the middle planes of the outer-ring and inner-ring magnets can be adjusted by adjusting the axial relative positions of the housing and the base. The isolator comprises a negative stiffness generating mechanism and a positive stiffness unit.

An isolation system and method are disclosed. The isolation system includes a beam that includes a first end and a second end. The isolation system may include at least one clamping block comprising first elastomeric material, and the first end may be coupled with the first elastomeric material by the at least one clamping block. An end condition of the buckling beam may be varied based on compression stiffening of the first elastomeric material.

Disclosed herein are a metastructure having a zero elastic modulus zone, which can experience constant stress in a predetermined strain zone, and a method for designing the same. The metastructure includes a first unit and a second unit, wherein the first unit has a structure capable of buckling and has a stress-strain relation having a zone corresponding to a negative elastic modulus, the second unit is disposed adjacent to the first unit and has a stress-strain relation having a zone corresponding to a positive elastic modulus, and the metastructure has zero elastic modulus in a predetermined target strain zone through synthesis of the negative elastic modulus of the first unit with the positive elastic modulus of the second unit.

The disclosure provides a magnetic suspension type quasi-zero stiffness electromagnetic vibration isolator with active negative stiffness. The disclosure relates to the technical field of vibration control. The disclosure can selectively realize passive negative stiffness and active negative stiffness by adjusting the control mode of a controller. By adopting an amplifying mechanism and DIESOLE type electromagnets, the bearing capacity of the vibration isolator is further increased, and the disclosure is suitable for the field of ultra-low frequency heavy load vibration reduction and isolation. The displacement state of a negative stiffness mechanism can be measured in real time according to a sensor, and by means of cooperation of the controller and a driver, active negative stiffness is realized, real-time linear negative stiffness is realized, the multi-stable phenomenon is avoided, and complex dynamic phenomena such as jumping during working of the vibration isolator are prevented. The active negative stiffness is realized, the current passing through the system can be adjusted according to different working conditions, and the system has strong self-adaptive ability, can be applied to vibration-isolated objects of different quality, and can adapt to different working environments.

The present invention relates to an elastic metamaterial for reducing vibrations of a flexible structure such as a main cable of a tether system for controlling an orbit of a satellite revolving around a planet, and a method for improving a vibration reduction performance thereof, and more particularly, to an elastic metamaterial having an improved precision, in which a ratio of a cross-sectional area of a pendulum ring may be adjusted to maintain a frequency characteristic other than a band gap generated due to the elastic metamaterial even in a state where a mass of the pendulum ring is not changed, and a band gap (R_ring) generated due to the pendulum ring of the elastic metamaterial and a band gap (R_beam) generated due to the elastic beams may be combined into one band gap to expand a vibration damping range, and a method for improving a vibration reduction performance thereof.