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Papers by Silviu-Cristian MELENCIUC
The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2011
Friction is a complex process, involving the simultaneous appearance of several phenomena such as... more Friction is a complex process, involving the simultaneous appearance of several phenomena such as wear, thermal, etc. Seismic protection of structures using frictional passive energy dissipaters is being lately used. Given that the coupled phenomenon can influence the behaviour over time of tribological assemblies, a thorough study of their effects is necessary in order to ensure a proper operation of frictional devices. In this respect, a method of analysis, commonly used today, is the finite element method. As with any approximate methods of calculus, this leads, in some cases, to partially correct results. This paper analyses the frictional heating phenomenon using the finite element method. Stress and the overall temperature distribution are presented for a particular case, as well as their dependence on the coefficient of friction and the force normally acting to the contact surface. The errors caused by this type of analysis are discussed also. ANSYS software was used for the ...
The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2011
The present design regulations require that the structural strength requirements should not preva... more The present design regulations require that the structural strength requirements should not prevail to the ductile behavior of structures in a design process. In case of steel columns bases, brittle failures (failure of holding-down bolts, concrete crushing in compressive zone) should be avoided. In this context, ductility or the rotational capacity should be determined mainly by the flexibility of baseplates. Experimental research studies may reveal specific local phenomena otherwise “invisible” (by numerical simulations, failure theories or other analysis methods). The main objective of this paper is to describe the overall structural behavior and evaluate the parameters involved in the connection design of the exposed rigid baseplate analysed in the laboratory test. The performed full-scale tests lead to failure modes validated by the maximum equivalent stress distributions numerically obtained.
The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2015
The high complexity of the load transfer mechanism at the steel column base connection yields for... more The high complexity of the load transfer mechanism at the steel column base connection yields for special care in both analysis/ design as well as in the actual errection stage of frame steel structures. Describing the real behaviour of the joint represents a key aspect in the overall structural analysis. The fully rigid or fully pinned assumptions on the column base joint behaviour have already been surpassed by more complex approaches in the analysis. As the dissipative capacity assessement is still under debate among specialists, the paper aims at delivering additional data to the problem. Laboratory tests, backed-up by numerical modeling investigations were performed on two natural scale steel columns base connection configurations under cyclic lateral loading conditions. Results of in terms of load - displacement and moment - rotation diagrams are hereinafter advanced for further studies purposes.
The finite element method is a numerical method that can be successfully used to generate solutio... more The finite element method is a numerical method that can be successfully used to generate solutions for problems belonging to a vast array of engineering fields: stationary, transitory, linear or nonlinear problems. For the linear case, computing the solution to the given problem is a straightforward process, the displacements are obtained in a single step and all the other quantities are evaluated afterwards. When faced with a nonlinear problems, in this case with a contact nonlinearity, one needs to account for the fact that the stiffness matrix of the systems varies with the loading, the force vs. stiffness relation being unknown prior to the beginning of the analysis. Modern software using the finite element method to solve contact problems usually approaches such problems via two basic theories that, although different in their approaches, lead to the desired solutions. One of the theories is known as the penalty function method, and the other as the Lagrange multipliers method...
The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2011
Friction is a complex process, involving the simultaneous appearance of several phenomena such as... more Friction is a complex process, involving the simultaneous appearance of several phenomena such as wear, thermal, etc. Seismic protection of structures using frictional passive energy dissipaters is being lately used. Given that the coupled phenomenon can influence the behaviour over time of tribological assemblies, a thorough study of their effects is necessary in order to ensure a proper operation of frictional devices. In this respect, a method of analysis, commonly used today, is the finite element method. As with any approximate methods of calculus, this leads, in some cases, to partially correct results. This paper analyses the frictional heating phenomenon using the finite element method. Stress and the overall temperature distribution are presented for a particular case, as well as their dependence on the coefficient of friction and the force normally acting to the contact surface. The errors caused by this type of analysis are discussed also. ANSYS software was used for the ...
The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2011
The present design regulations require that the structural strength requirements should not preva... more The present design regulations require that the structural strength requirements should not prevail to the ductile behavior of structures in a design process. In case of steel columns bases, brittle failures (failure of holding-down bolts, concrete crushing in compressive zone) should be avoided. In this context, ductility or the rotational capacity should be determined mainly by the flexibility of baseplates. Experimental research studies may reveal specific local phenomena otherwise “invisible” (by numerical simulations, failure theories or other analysis methods). The main objective of this paper is to describe the overall structural behavior and evaluate the parameters involved in the connection design of the exposed rigid baseplate analysed in the laboratory test. The performed full-scale tests lead to failure modes validated by the maximum equivalent stress distributions numerically obtained.
The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2015
The high complexity of the load transfer mechanism at the steel column base connection yields for... more The high complexity of the load transfer mechanism at the steel column base connection yields for special care in both analysis/ design as well as in the actual errection stage of frame steel structures. Describing the real behaviour of the joint represents a key aspect in the overall structural analysis. The fully rigid or fully pinned assumptions on the column base joint behaviour have already been surpassed by more complex approaches in the analysis. As the dissipative capacity assessement is still under debate among specialists, the paper aims at delivering additional data to the problem. Laboratory tests, backed-up by numerical modeling investigations were performed on two natural scale steel columns base connection configurations under cyclic lateral loading conditions. Results of in terms of load - displacement and moment - rotation diagrams are hereinafter advanced for further studies purposes.
The finite element method is a numerical method that can be successfully used to generate solutio... more The finite element method is a numerical method that can be successfully used to generate solutions for problems belonging to a vast array of engineering fields: stationary, transitory, linear or nonlinear problems. For the linear case, computing the solution to the given problem is a straightforward process, the displacements are obtained in a single step and all the other quantities are evaluated afterwards. When faced with a nonlinear problems, in this case with a contact nonlinearity, one needs to account for the fact that the stiffness matrix of the systems varies with the loading, the force vs. stiffness relation being unknown prior to the beginning of the analysis. Modern software using the finite element method to solve contact problems usually approaches such problems via two basic theories that, although different in their approaches, lead to the desired solutions. One of the theories is known as the penalty function method, and the other as the Lagrange multipliers method...