In: Civil Engineering
What factors discourage the use of redundant members or novel materials in bridge design?
What role should inspections/maintenance play in structural design?
What is a strain gauge? How does it work? How can it be used to prevent structural failure?
The factors which are mainly discourage the use of reduntant members or novel materials in bridge design that are:
i) High cost for major river crossings
ii) use of reduntant members or novel materials may increse the load carrying capacity of the bridge, but it also increse the self weight of the bridge. If the river bed soil has not high bearing capacity , bridge may collapse.
iii) For minor or short river, where the reduntant member is not necessaary, there it is completely ignored.
✓✓ There is an important role play of maintanance for structural design mainly for steel design members, that are
i) corrosion check
ii) connections check i.e bolts are in well connected or welding is performing well or not
iii) crack check i.e in structure there is any crack happend or not
iv) elongation check, mainly in summer steel materials are elongated due to heat, so we have to check the elongation are in permissible limit or not.
✓✓strain gauge, as its name defined the instrument which measure strain value. Strain gauge mainly a transducer, which can measure the strain by electrical resistance.
In this instrument, anything force we can applied like tension,compression, weight, pressure , the instrument converts it to the electrical resistance by its sensor property. And the strain( mainly tension or compression, for tension it is positive and for compression it is negative) happens with respect to the force it gives the strain result.along with stress value.
✓✓✓ Though it can measure the both stress and strain value for any kind force value, definately it is an important instrument to prevent the structural failure. As we know stress and strain are the major two parameters for checking of any kind of structural design, either it is safe or not. So by this instrument we should check either the structure is reached to its permissible failure stress value or not and either the strain value is in permissible limit or not. In this way, we can be predetermined to structural failure by this instrument.