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Lamb wave propagation must be understood comprehensively for simply evaluating delamination during ultrasonic testing. However, the difference between wave propagation, visualized using laser Doppler vibrometer and pulsed-laser scanners, has not been sufficiently investigated, and knowledge of optimal conditions for evaluating delamination is limited. Thus, in this study, the mode conversion and multiple reflections of Lamb waves propagating in a delaminated cross-ply laminate were visualized using different laser scanners, delamination depths, and wave incident angles. Delamination was characterized using maximum-amplitude map postprocessing under specific conditions. Further numerical analysis revealed that owing to multiple reflections of the antisymmetric mode in incident and mode-converted waves, standing waves were generated in the delaminated sublaminate. Dispersion curve and flexural stiffness calculations confirmed the conditions required for high-amplitude standing waves, thereby providing guidelines for simply and reliably evaluating delamination during inspections. [ABSTRACT FROM AUTHOR]

Introduction: Herein, we describe a novel technique for suprapubic incisional hernia repair using a modified transabdominal partial extraperitoneal technique in four patients. Materials and Surgical Technique: We implemented four‐trocar placement to achieve a coaxial setting for the pubic bone. The pubic bone and Cooper's ligament were exposed by an incision dorsal to the hernial orifice, and the bladder was mobilized as an inferior peritoneal flap. The retropubic space was dissected approximately 5 cm from the hernial defect and this was closed with an intracorporeal non‐absorbable barbed suture. A mesh was introduced into the intra‐abdominal cavity, positioned to cover the closed defect, and tied to Cooper's ligament, the pubic bone, and rectus muscles. The dissected peritoneal flap was reattached to the abdominal wall by tacking and suturing. Discussion: The modified transabdominal partial extraperitoneal technique for suprapubic incisional hernia repair may contribute to decreased recurrence and seroma formation. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced plastics (CFRP) laminate structures manufactured using prepregs usually contain fiber discontinuities that result from the prepreg cutting for design and cost-efficiency. In this study, the sampling moiré method was used to measure the microscopic strain of unidirectional CFRP laminates with fiber discontinuities to investigate the deformation behavior that causes damage. In addition to the strain distributions of the laminate before and after cracking, the strain results due to thermal residual stress relaxation and residual plastic deformation during cracking were also obtained. The experimental results of this study were in good agreement with the finite element method results. Our results revealed that the sampling moiré method is an accurate method of measuring microscopic strain that can be used to evaluate the mechanical properties, damage behavior, residual strains in laminates with fiber discontinuities, and other different materials and structures. [ABSTRACT FROM AUTHOR]

Introduction: Surgical techniques to close defects in laparoscopic incisional hernia repair vary across the literature. We herein demonstrate our original and standardized surgical technique for laparoscopic incisional hernia repair with complete intracorporeal defect closure using barbed suture. Materials and Surgical Technique: Complete intracorporeal defect closures were indicated for defects less than or equal to 6 cm in transverse diameter. We performed a defect closure with a running suture using barbed suture in a caudal to cranial direction, with tissue bites and inter‐suture spacing of 1 cm each. The hernial sac was incorporated into the suturing to reduce possible dead space. After the procedure, intraperitoneal onlay mesh was placed. Seven patients underwent this procedure. The median total operative time was 188 min, and the median time specifically for defect closure was 25 min. There was no seroma, mesh bulge, persisting pain, or hernia recurrence at follow‐up. Discussion Our proposed technique is simple and can be safely performed with good short‐term outcomes. [ABSTRACT FROM AUTHOR]

Byline: Byung-Koog Jang, Nobuyuki Toyama, Ja-Ho Koo, Teruo Kishi TiNi/CFRP composites were fabricated by sandwiching TiNi wires between layers of CFRP prepreg by hot-pressing in the temperature range of 150-180uC, by controlling the applied pressure. The microstructural properties of hot-pressed TiNi/CFRP composites were investigated by SEM. The tensile strength of CFRP monolith not embedded with TiNi wires is 1.3GPa, whereas that of TiNi/CFRP composites is about 1.2GPa. The fracture behavior was studied by an AE technique under tensile test, to analyse the fracture process. It was confirmed that the detected AE signals resulted from generation of fibre breakage, interfacial debonding and microcracks in the epoxy matrix. The damage recovery effect of fractured specimens was successfully obtained by heating above 80uC.

In this study, we propose an ultrasonic inspection technique for detecting disbonds in adhesively bonded carbon fiber-reinforced plastics (CFRP)/aluminum joints using pulsed laser scanning. A specimen with artificially induced square disbonds was scanned by a pulsed laser for ultrasound generation, and the propagating waves were received by a transducer placed on its surface. A series of images of the traveling waves were obtained by processing the received signals. An initial, quick inspection was performed using low-frequency Lamb waves. Changes in the propagation of the Lamb waves were observed at the disbond regions, and disbonds larger than 5 × 5 mm² were successfully detected. A second, detailed inspection of the detected disbond regions was performed using the high-frequency through-transmission ultrasonic method. The shape of the disbond was precisely imaged, and the evaluated size of the disbond matched well with the actual size. We thus demonstrated the efficiency and the feasibility of the proposed technique for the inspection of adhesively bonded CFRP/Al joints. [ABSTRACT FROM AUTHOR]

This study demonstrates a rapid non-contact ultrasonic inspection technique by visualization of Lamb wave propagation for detecting impact damage in carbon fiber reinforced polymer (CFRP) laminates. We have developed an optimized laser ultrasonic imaging system, which consists of a rapid pulsed laser scanning unit for ultrasonic generation and a laser Doppler vibrometer (LDV) unit for ultrasonic reception. CFRP laminates were subjected to low-velocity impact to introduce barely visible impact damage. In order to improve the signal-to-noise ratio of the detected ultrasonic signal, retroreflective tape and a signal averaging process were used. We thus successfully visualized the propagation of the pulsed Lamb A0 mode in the CFRP laminates without contact. Interactions between the Lamb waves and impact damage were clearly observed and the damage was easily detected through the change in wave propagation. Furthermore, we demonstrated that the damage could be rapidly detected without signal averaging. This method has significant advantages in detecting damage compared to the conventional method using a contact resonant ultrasonic transducer due to the absence of the ringing phenomenon when using the LDV. [ABSTRACT FROM AUTHOR]