What is hyperstatic?

What is hyperstatic?

hyperstatic in British English (ˌhaɪpəˈstætɪk) adjective. (of a building) having excessive or redundant support components.

What is hyperstatic force?

ABSTRACT. Hyperstatic forces develop in an indeterminate structure. These forces result when the imposed deformations due to prestressing are restrained or prevented by the support conditions of the structure.

What are secondary moments?

• Secondary moment – The secondary moments are additional moments induced at a section due to resultant reactions developed as an effect of the prestressing structure. – The secondary moment of the two spans continuous beam is shown in figure.

What are secondary prestress effects?

Secondary (parasitic) effects of prestressing develop in hyperstatic structures (continuous beams) due to restraining of imposed deformation by hyperstatic restraints. These effects may, in some case, significantly influence internal forces and stresses in prestressed structures.

What is Hyperstatic structure?

Add. In statics, a structure is statically indeterminate (or hyperstatic) when the static equilibrium equations are insufficient for determining the internal forces and reactions on that structure.

What is isostatic structure?

This paper deals with isostatic frameworks, i.e., pin-jointed bar assemblies, commonly referred to in engineering literature as truss structures, that are both kinematically and statically determinate. Such systems are minimally infinitesimally rigid and maximally stress free: they can be termed ‘just rigid’.

When an indeterminate structure is prestressed which reactions develop?

Explanation: When an indeterminate structure is prestressed, reductant reactions will develop due to the redundancies exercising a restraint at the supports and the redundant reactions which develop as a consequence of prestressing an indeterminate structure result in secondary moments.

What is the primary moment of PSC member?

Explanation: The primary moment is the apparent bending moment at a section in a statically indeterminate structure due to the actual eccentricity of the tendons from the centroid axis and primary moment at every cross section of the two span continuous beams is Pe as it is a hogging moment.

Which is the resultant moment of PSC member is known as?

Explanation: The combined effect of prestressing force and the externally applied load will result in a distribution of concrete stresses that can be resolved into a single force and the locus of the points of application of this resultant force in any structure is termed as “pressure or thrust line”.

What do you mean by loss of prestress?

The prestress losses are defined as the loss of tensile stress in the prestress steel which acts on the concrete component ofthe prestressed concrete section. In pretensioned concrete, the four major sources of prestress losses are elastic shortening (ES), creep (CR), shrinkage (SH) and relaxation (RE).

Where do you adopt circular pre stressing?

Circular prestressing is also applied in domes and shells. The circumferential prestressing resists the hoop tension generated due to the internal pressure. The prestressing is done by wires or tendons placed spirally, or over sectors of the circumference of the member.

What are the effects of hyperstatic forces and moments?

The hyperstatic forces and moments are the difference between the unrestrained (primary) and the restrained (balance) results. The effects of both tendons and restraint must be considered for each design rule: service, strength, etc. Typically, the effects are considered differently in service and strength design.

How are hyperstatic forces calculated at a cross section?

This can be calculated at any cross section based purely on the cross section geometry and the tendon location. The hyperstatic forces and moments are the difference between the unrestrained (primary) and the restrained (balance) results.

What’s the difference between balance and hyperstatic loading?

The following equation is important in understanding the difference between Balance and Hyperstatic Loading: The balance loading considers all the loads that the tendon puts on the concrete. These include the force results (axial, shear, and moments) in the slab and the restraint (reactions) of the supports.