Search results for "Punching"
showing 6 items of 6 documents
Vibration Control of a High-Speed Precision Servo Numerically Controlled Punching Press: Multidomain Simulation and Experiments
2017
A three-degree-of-freedom mathematical vibration model of a high-speed punching press was developed in order to explore the vibration modes of the punching press. A multidomain model of the punching press was established to predict the kinematic state during different conditions, as well as the effects of load fluctuation on the motor speed. Experimental measurements of the acceleration of the punching press were carried out. The results comparison reveals that the multidomain model is consistent with the vibration model and the experimental measurements. Modal analysis and structure modification of the punching press were conducted. The foundation at the base of the punching press was impr…
Practical Calculation Models for Column Footing and Comparison with Experimental Data
2017
In this paper, a simplified calculation model for the prediction of the load-carrying capacity of an RC column footing with a square cross section is presented. A detailed background of available experimental data and existing models for the prediction of the load-carrying capacity of slender and deep footings is presented. Cases of flexural failure and punching shear failures for slender footing and concrete strut crushing and tie yielding in deep members are analyzed. The aim of the paper is to propose a simple design formula for slender and deep footing verified by available experimental data and in agreement with other existing expressions. Expressions of the maximum mechanical ratio of…
Electrical energy analysis and potential environmental improvements of sheet metal punching processes
2013
Discrete part manufacturing processes, in particular non-conventional production processes, are still poorly documented in terms of environmental footprint. Within the separating processes, sheet metal punching processes have not been analyzed yet from environmental point of view. The present paper aims to contribute to filling this knowledge gap. In particular, two different punching machine tool architectures were analyzed. Following the previously developed CO2PE methodological approach, power studies and a preliminary time study have been performed in order to understand the contribution of each sub-unit towards the total energy demand. The influence of the most relevant process paramet…
Simplified model for compressive response of RC column footing with square cross-section
2017
Abstract In this paper, a simplified calculus model for the prediction of the compressive response of RC column footing with a square cross-section is presented. As it is well-known RC concrete footing are designed adopting uniform contact pressures on the substrate and assuming a strut and tie model in deep members and a cantilever beam or slab model in flexible members. Deep and flexible members are distinguished in literature only based on the tangent of the angle expressed as the ratio between the depth and the shear span of the footing. In this paper, several subgrade contact pressures distribution for column footings (rigid or soft soils) were considered in developing a mechanical mod…
Influence of oblique edge blanking on the online punching quality after stretch bending
2018
The oblique edge punching was proposed to reduce the surrounding sag failure occurred under the large punching force during online punching after stretch bending. The finite element models under three different kinds of punches were stablished and the punching processes were simulated by using the DEFORM-3D software. Comparison between the flat-edge punch and the oblique edge punches were realized, and the optimal height of the oblique edge of the unilateral bevelled punch and the single-peak bevelled punch were obtained. Three kinds of punches were designed based on the simulation results, and the experiments for manufacturing the upper strip of the automobile door frame by the online punc…
Practical Model for Load-Carrying Capacity of Eccentrically Loaded Square Column Footings
2018
In this paper, a practical calculus model based on the strut-and-tie approach for prediction of the load-carrying capacity of eccentrically loaded RC column footings with square cross sections is presented. Existing models based on beam or slab models with flexural and two-way slab punching shear failure are presented and discussed. Several subgrade contact pressure distributions for column footings are considered. A parametric analysis of the effects of footing and column dimensions (depth, width), longitudinal ratio of longitudinal steel, and strength of concrete and steel is made for all models examined. Available experimental data are utilized to verify the model in comparison with exis…