Virtual Prototyping of a Parallel Robot actuated by Servo-Pneumatic Drives using ADAMS / Controls
Advanced pneumatic drives for servo-pneumatic positioning allow for new generations of handlings and robots. Especially parallel robots actuated by servo-pneumatic drives allow the realization of very fast pick and place tasks in 3-D space. The design of those machines requires a virtual prototyping method called the mechatronic design [ 1]. The most suitable software tools are ADAMS for mechanics and Matlab/Simulink for drives and controllers. To analyze the overall behavior the co-simulation using ADAMS/Controls is applied. The combination of these powerful simulation tools guarantees a fast and effective design of new machines.
TRIPLANAR-a new process-machine type developed by means of the mechatronics design
TRIPLANAR is the name for a new machine type with six degrees of freedom. It serves for highly precise processing and measurement tasks. The design principle with new parallel kinematics was proposed by Mechatronics Laboratory Paderborn. An optimal design (both hardware and software) of the system can only be achieved by applying the so-called mechatronics design method. The core of this method is the consideration of the overall system including the interactions of all components involved. Special attention is paid to the actuators of the machine. These consist of three planar hybrid steppers each serving for two directions. The drives applied, however, are converted into servo drives which allow the actuator to induce a force into the mechanical system. The modelling of the drives is explained in greater detail.
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.