So we are doing this project on conducting an experiment to investigate the Statical Equilibrium of Plane Frameworks. Why do we need to conduct such experiments when we can easily calculate by hand and by pin-joint analysis.
There are several general reasons for conducting practical tests in addition to theoretical analysis.
- to verify that the theoretical approach and associated assumptions are valid. Pretty much all loading models involve some simplifications and assumptions.
- for quality assurance : practical tests can pick up manufacturing/material defects, design errors and mis-communications between the design and manufacture stages
- regulatory approval : slapping a load on a structure is a lot easier to implement than verifying calculations especially in non-standard cases.
- practical testing verifies the whole product which can actually be less trouble than documenting every single stage of design and production.
You don't say if this is an academic project, if so it may simple be a case that the course wants to teach/evaluate both theoretical and practical skills. A huge aspect of real world engineering is having a sense of how theoretical models relate to reality and understanding that all models contain assumptions which may not always be valid.