Support apparatus for modal test and using method thereof

A support apparatus for a modal test, comprising

• a suspension structure, configured to suspend a test unit;
• and
• a support structure, disposed under the suspension structure and configured to support the test unit, the suspension structure and the support structure being matched to cause a stiffness of the support apparatus for a modal test to be zero;
• the support structure comprising an anti-stiffness rhombus-shaped frame, a scalable sleeve, a horizontal elastic component, and a base, the base being disposed under the anti-stiffness rhombus-shaped frame, the scalable sleeve being connected to the anti-stiffness rhombus-shaped frame and the base respectively, and the horizontal elastic component connecting two diagonal points of the anti-stiffness rhombus-shaped frame;
• wherein
• the suspension structure comprises a suspension crossbeam, a first elastic component, and a second elastic component, the first elastic component and the second elastic component are horizontally connected to the suspension crossbeam and configured to suspend the test unit, and the first elastic component and the second elastic component have the same elastic stiffness coefficient, and the elastic stiffness coefficients of the first elastic component and the second elastic component are a half of an elastic stiffness coefficient of the horizontal elastic component;
• the anti-stiffness rhombus-shaped frame comprises a first rhombus-shaped frame support rod, a second rhombus-shaped frame support rod, a third rhombus-shaped frame support rod and a fourth rhombus-shaped frame support rod that are connected successively and a first hinge, a second hinge, a third hinge, and a fourth hinge, the first rhombus-shaped frame support rod and the second rhombus-shaped frame support rod are articulated via the first hinge, the second rhombus-shaped frame support rod and the third rhombus-shaped frame support rod are articulated via the second hinge, the third rhombus-shaped frame support rod and the fourth rhombus-shaped frame support rod are articulated via the third hinge, and the fourth rhombus-shaped frame support rod and the first rhombus-shaped frame support rod are articulated via the fourth hinge.