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A laser welding with wire filler feeding was developed to replace traditional arc welding process for joining aluminium alloy railcar body components. A three-dimensional (3D) thermo-elastic-plastic finite element (FE) model was applied to compute the plastic strains of weld zone in a downsized aluminium alloy plate with butt-joint, T-joint and fillet-joint configurations, respectively, combined with corresponding experimental validations. The achieved plastic strains at the weld zone were then input as inherent strain loadings into elastic structural FE model of fully sized aluminium alloy railcar body components to predict the welding induced distortion with the experimentally measured out-of-plane distortions. The experimentally validated FE model was then further applied for optimizing the inverse pre-deformation of plates to counteract the welding induced deformation, finally to mitigate the welding distortion issues. [ABSTRACT FROM AUTHOR]

Background: To improve minimally invasive outcomes, we designed a new procedure, lower abdominal laparoscopic cholecystectomy (LALC). This study was conducted to evaluate the effects of LALC versus classical (CLC) and single-incision (SILC) laparoscopic cholecystectomy on reducing systemic acute inflammatory response, improving cosmesis, and postoperative pain relief. Material and methods: Beginning from July 2014, 105 patients meeting the inclusion criteria were randomly assigned to three groups: LALC, CLC, and SILC. The primary endpoint was the determination of systemic inflammatory response to the surgery. Other outcome measures included cosmesis, postoperative pain, and perioperative indices. Results: Each of the three groups consisted of 35 patients. The duration of the operation was significantly longer in the SILC group (p = .005). The rates of adverse events were similar. Changes in interleukin-6 (p = .001) and tumor-necrosis factor-α (p = .016) measured before and after surgery differed significantly; patients who underwent LALC had the smallest change in inflammatory response. Cosmesis scores at one (p = .002) and 12 (p = .004) weeks after surgery favored LALC and SILC. Significant differences in pain scores at four (p = .011) and 12 h (p = .024) postoperatively were also observed. Conclusions: In selected patients, LALC shows more advantages in terms of lower systemic inflammatory response, improved cosmesis, and a favorable postoperative pain profile when compared with CLC and SILC. [ABSTRACT FROM AUTHOR]