Investigation of simple stability problems (SE 110.19)

Investigation of simple stability problems (SE 110.19)

representation of simple stability problems on a buckling bar



  • 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:


  • 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


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


  • 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.