A selectively tunable vibration absorber includes a support member having an outer surface, and a selectively tunable element mounted relative to the outer surface of the support member. The selectively tunable element is selectively adjustable to attenuate vibrations in a selected frequency range perceived by the support member in a selected direction. A mass is supported by the selectively tunable element.

A selectively tunable vibration absorber includes a support member having an outer surface, and a selectively tunable element mounted relative to the outer surface of the support member. The selectively tunable element is selectively adjustable to attenuate vibrations in a selected frequency range perceived by the support member in a selected direction. A mass is supported by the selectively tunable element.

A vibration-proof fastener post structure includes a body portion having a first end integrally formed with or assembled to a first object; a fastening head portion movably mounted to a second end of the body portion and having a neck portion, which is movably disposed in the body portion for moving in a slideway hole of a second object; and an elastic element movably fitted around the neck portion to push against the body portion. The fastening head portion and the body portion are configured for engaging with and fastening to the slideway hole of the second object. The second object is slidably relative to the neck portion. When the second object is slid to a predetermined position, the fastening head portion and the elastic element, the body portion or the pushing member will engage with the slideway hole of the second object to achieve a vibration-proof fastening effect.

A vibration-proof fastener post structure includes a body portion having a first end integrally formed with or assembled to a first object; a fastening head portion movably mounted to a second end of the body portion and having a neck portion, which is movably disposed in the body portion for moving in a slideway hole of a second object; and an elastic element movably fitted around the neck portion to push against the body portion. The fastening head portion and the body portion are configured for engaging with and fastening to the slideway hole of the second object. The second object is slidably relative to the neck portion. When the second object is slid to a predetermined position, the fastening head portion and the elastic element, the body portion or the pushing member will engage with the slideway hole of the second object to achieve a vibration-proof fastening effect.

A fast and economical system and methods directed to low-fidelity fabrication of three-dimensional (3D) objects using 3D printing. The invention facilitates rapid prototyping by providing a wireframe structure in the form of the underlying design structure of a 3D model, which may be useful for a variety of reasons including to provide a prototype preview that may be used for design validation of a 3D model.

A vibration-proof fastener post structure includes a body portion having a first end integrally formed with or assembled to a first object; a fastening head portion movably mounted to a second end of the body portion and having a neck portion, which is movably disposed in the body portion for moving in a slideway hole of a second object; and an elastic element movably fitted around the neck portion to push against the body portion. The fastening head portion and the body portion are configured for engaging with and fastening to the slideway hole of the second object. The second object is slidably relative to the neck portion. When the second object is slid to a predetermined position, the fastening head portion and the elastic element, the body portion or the pushing member will engage with the slideway hole of the second object to achieve a vibration-proof fastening effect.

A vibration-proof fastener post structure includes a body portion having a first end integrally formed with or assembled to a first object; a fastening head portion movably mounted to a second end of the body portion and having a neck portion, which is movably disposed in the body portion for moving in a slideway hole of a second object; and an elastic element movably fitted around the neck portion to push against the body portion. The fastening head portion and the body portion are configured for engaging with and fastening to the slideway hole of the second object. The second object is slidably relative to the neck portion. When the second object is slid to a predetermined position, the fastening head portion and the elastic element, the body portion or the pushing member will engage with the slideway hole of the second object to achieve a vibration-proof fastening effect.

Provided is an adjusting method for a resonance frequency of a vibration isolator, the vibration isolator including first to n-th elastic member groups and/or an n+1-th elastic member group, the first to n-th elastic member groups and/or the n+1-th elastic member group being located on an xy plane of an xyz coordinate system, and an xy coordinate system of the xyz coordinate system being a coordinate system obtained by, when a tensor of inertia I with respect to an XYZ coordinate system having an origin in a center of gravity of a vibration sensing side structure or a vibration source side structure is represented as I, rotating an XY coordinate system by =tan.sup.1(2I.sub.XY/(I.sub.XXI.sub.YY)) around a Z axis, the adjusting method including, when rigidity K.sub.i of the first to n-th elastic member groups is represented as

[00001]$\left[K_i\right]=\left[\begin{array}{ccc}{k}_{i.Math.\_.Math.\mathrm{xx}}& 0& 0\\ 0& k_{i.Math.\_.Math.\mathrm{yy}}& 0\\ 0& 0& k_{i.Math.\_.Math.\mathrm{zz}}\end{array}\right],$

rigidity K.sub.n+1 of the n+1-th elastic member group is represented as

[00002]$\left[K_{n+1}\right]=\left[\begin{array}{ccc}{k}_{n+1.Math.\_.Math.\mathrm{xx}}& 0& 0\\ 0& k_{n+1.Math.\_.Math.\mathrm{yy}}& 0\\ 0& 0& k_{n+1.Math.\_.Math.\mathrm{zz}}\end{array}\right],$

A vibration-proof fastener post structure includes a body portion having a first end integrally formed with or assembled to a first object; a fastening head portion movably mounted to a second end of the body portion and having a neck portion, which is movably disposed in the body portion for moving in a slideway hole of a second object; and an elastic element movably fitted around the neck portion to push against the body portion. The fastening head portion and the body portion are configured for engaging with and fastening to the slideway hole of the second object. The second object is slidably relative to the neck portion. When the second object is slid to a predetermined position, the fastening head portion and the elastic element, the body portion or the pushing member will engage with the slideway hole of the second object to achieve a vibration-proof fastening effect.

A vibration-proof fastener post structure includes a body portion having a first end integrally formed with or assembled to a first object; a fastening head portion movably mounted to a second end of the body portion and having a neck portion, which is movably disposed in the body portion for moving in a slideway hole of a second object; and an elastic element movably fitted around the neck portion to push against the body portion. The fastening head portion and the body portion are configured for engaging with and fastening to the slideway hole of the second object. The second object is slidably relative to the neck portion. When the second object is slid to a predetermined position, the fastening head portion and the elastic element, the body portion or the pushing member will engage with the slideway hole of the second object to achieve a vibration-proof fastening effect.