representation of simple stability problems on a buckling bar

Description:

• Buckling is a stability problem which occurs in practice when slim components are subjected to compressive loading.
• Following a “disturbance” to its equilibrium, such as caused by compressive loading, a stable system returns to equilibrium when the loading is removed.
• If the compressive load increases excessively, instability of the system results.
• The component buckles and fails.
• The critical compressive load at which the system becomes unstable is termed the buckling force.
• A simple model for representing stability problems is a two-part bar with an elastic joint which remains stable up to a certain load level.
• If the buckling force is exceeded, the bar suddenly buckles and so becomes unstable.
• SE 110.19is used to investigate simple stability problems on a buckling bar under different conditions.
• The buckling bar is in two parts, with a central articulated joint.
• A compressive load is applied to the bar by a lever and weights.
• The continuously variable loading is determined precisely with the aid of a scale on the load application lever.
• Experiments can depict a variety of conditions, such as an elastic joint or an elastic clamp fixing.
• Two tension springs serve as the elastic joint. For the elastic clamp fixing option, a steel leaf spring is mounted in the bottom joint.
• The variable length of the leaf spring means various degrees of clamping are possible.
• The two cases can be combined.
• Another experiment demonstrates the influence of additional shear forces.
• It involves applying a shear force to the joint in the buckling bar with a cable and a weight.
• In all experiments the buckling bar is placed under load until it reaches an unstable situation.
• The length of the lever arm at which the buckling bar buckles is read from the scale and the buckling force is then determined.
• All the component elements of the experiment are clearly laid-out and housed securely in a storage system.
• The complete experimental setup is arranged in the frame SE 112.

Technical Details:

Specifications:

• investigation of the buckling load under different conditions (elastic joint, elastic fixed end)
• two-part buckling bar with central joint
• loading continuously variable with lever and weights
• determination of loading via scale on load application lever
• various degrees of clamping via leaf spring with variable length on bottom support
• thrust pad guided friction-free inside spherical shell
• low-friction joints with roller bearings
• device to generate shear forces
• storage system to house the components
• experimental setup in frame SE 112

Technical Data:

• Two-part buckling bar with central joint:
  • WxH: 20x20mm
  • length: 2x250mm
  • support: pinned-pinned (articulated-articulated)
• Elastic joint:
  • 2 tension springs, rigidity: 2N/mm
  • lever arm: 50mm
• Elastic clamp fixing with steel leaf spring
  • length: 500mm
  • cross-section: 10x2mm
  • second moment of area: 6,66mm⁴
  • modulus of elasticity: 205000N/mm²
• Compressive force range: 25…120N
• Shear force: 0…20N
• Load application lever, lever ratio: 1:2…1:5
• Weights:
  • 2x 1N (hanger)
  • 8x 1N
  • 6x 5N

Dimensions & Weight:

• L x W x H: 1170x480x178mm (storage system)
• Weight: approx. 28kg (total)

Learning Objectives/Experiments:

• determination of the buckling force for the case of an:
• elastic joint
• elastic fixed end support
• investigation of the buckling behaviour under the influence of:
• of additional shear forces
• of pre-deformation

Scope of delivery:

• 1 buckling bar, two-part
• 1 set of weights
• 4 supports
• 1 deflection roller
• 1 load application lever
• 1 leaf spring
• 2 tension springs
• 1 cord
• 1 hexagon socket wrench
• 1 storage system with foam inlay
• 1 set of instructional material

Features:

• determination of the buckling load under different conditions
• continuously variable load application on the buckling bar

Accessories:

• Required: SE 112 Mounting frame

Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.