DIFFRENCE BETWEEN STATICALLY DETERMINATE AND INDETERMINATE STRUCTURE

 A statically determinate structure is such structure for which conditions of static equilibrium are sufficient to analyze the structure.

While for statically indeterminate structure, the conditions of static equilibrium equations are not sufficient to analyze the structure. Compatibility condition or equilibrium equation will be required to fully analyze the structure.

For statically determinate structures, the internal reactions like shear force and bending moment are independent of properties of material used and cross sectional area. This means that shear force and bending moment will not depend on material properties and cross sectional area. While for indeterminate structure, they depends on these properties.

For statically indeterminate structures, no stresses are induced in structure due to temperature change. While for indeterminate structures. change in temperature will induce stresses.

For statically determinate structures, no stresses are induced due to lack of fit and support settlement. This means that misfits and settlement of support will not generate any stress in statically determinate structure. While for indeterminate structure, stresses are induced due to same.

For a certain amount of loading, in general there will be higher stress induced in statically determinate structure  in comparison to indeterminate structure. Even the deflection produced in case of statically determinate structure is higher in comparison of indeterminate structure.

Due to lesser stress induced in indeterminate structure, there will be cost saving in material in indeterminate structure. But the cost of producing support and joints in indeterminate structure will offset the cost of saving in material.