The principal resonance of Van der Pol-Duffing oscillator to combined deterministic and random parametric excitations is investigated. The method of multiple scales was used to determine the equations of modulation of...The principal resonance of Van der Pol-Duffing oscillator to combined deterministic and random parametric excitations is investigated. The method of multiple scales was used to determine the equations of modulation of amplitude and phase. The behavior, stability and bifurcation of steady state response were studied. Jumps were shown to occur under some conditions. The effects of damping, detuning, bandwidth, and magnitudes of deterministic and random excitations are analyzed. The theoretical analysis were verified by numerical results.展开更多
The modern and updated use of traditional materials in the building industry often proves to improve the performance of the buildings through the economy of management, duration, conditions of comfort and safety, appe...The modern and updated use of traditional materials in the building industry often proves to improve the performance of the buildings through the economy of management, duration, conditions of comfort and safety, appearance and shelf life. Within this problem a search has allowed us to verify a new building procedure based on the use of reinforced masonry with blocks of natural stone and steel bars and mortar. Then a new phase of research has defined the building procedure of prestressed reinforced masonry with dry-assembled blocks of natural stone. This paper reports the results from a test phase of the research relating to the execution of a full-scale prototype of a panel, with a curved shape, called ＂stone sail＂. This testing allows us to verify the real feasibility of the new building procedure.展开更多
文摘The principal resonance of Van der Pol-Duffing oscillator to combined deterministic and random parametric excitations is investigated. The method of multiple scales was used to determine the equations of modulation of amplitude and phase. The behavior, stability and bifurcation of steady state response were studied. Jumps were shown to occur under some conditions. The effects of damping, detuning, bandwidth, and magnitudes of deterministic and random excitations are analyzed. The theoretical analysis were verified by numerical results.
文摘The modern and updated use of traditional materials in the building industry often proves to improve the performance of the buildings through the economy of management, duration, conditions of comfort and safety, appearance and shelf life. Within this problem a search has allowed us to verify a new building procedure based on the use of reinforced masonry with blocks of natural stone and steel bars and mortar. Then a new phase of research has defined the building procedure of prestressed reinforced masonry with dry-assembled blocks of natural stone. This paper reports the results from a test phase of the research relating to the execution of a full-scale prototype of a panel, with a curved shape, called ＂stone sail＂. This testing allows us to verify the real feasibility of the new building procedure.
