Theoretical and experimental study on optimal cropping load control strategy of duralumin alloy AlCu4Mg1 based on linear elastic fracture mechanics

Abstract

In this work, a metal bar fine-cropping system is designed to study the influence load control strategies based on theoretical and cropping experiments. The principle of the new cropping system and mechanical compositions system are introduced. Three different load control strategies are designed based on duralumin alloy AlCu4Mg1 bar, and the optimal loading order is determined under them. According to a new proposed cross-section quality evaluation method, the test results show constant stress intensity factor range of external load ([Formula: see text]), linear decreasing cyclic load of appropriate time coefficient ([Formula: see text]) can obtain better cropping effect and the best quality is obtained by the loading cycle ([Formula: see text]).

Research on damage evolution and fracture prediction in hydraulic continuous rotary bending low-stress cropping

“…4. According to the material strength and engineering fracture mechanics theory, as well as Zhong's research [7][8] , the fracture of notched structures under bending moment is frequently influenced by process parameters such as loading amplitude, loading position, loading frequency, and notch geometric parameters. The control of loading position of the displacement load plays a crucial role in governing the damage accumulation, crack initiation, crack propagation, and fracture behavior of notches root on the bar surface under the same geometric parameters of the notch.…”

“…1. Zhong [7][8] developed a pneumatic bending fatigue LSC system, and studied the reasonable load control curve by the linear elastic fracture mechanics theory. Xu [9] investigated the cross-section quality of the rotary bending LSC method using the extended finite element method(XFEM) and catastrophic theory.Zhang [10] studied the critical crack initiation load of hydraulically compensated LSC method by using the stress concentration factor and XFEM.Although many new LSC methods have been proposed [11][12] , it is difficult to realise the industrialisation of this cropping technology, mainly because the mechanism of this cropping method mostly adopts the equivalent treatment of the crack propagation mechanism, without consideration of the damage accumulation of material internal defect.…”

Effect of Notch on Strain Rate Concentration Factor of 304 Stainless Steel Bar

“…304 stainless steel is widely used in industrial application because of its good mechanical properties and corrosion resistance [1,2]. For example, metal chains, bearings, and various bearing parts, and all shaft-related parts are processed using metal bar material cropping [3,4]. e quality cross section directly affects the machining quality and production efficiency of the subsequent parts.…”