Topological Shape Optimization Design of the Whole Bead of 265/35R18 Steel-Belted Radial Tire

The tire bead, as the most important load-bearing component at the bead area, is closely related to the durability of the tire, but its structure is developing slowly. For this reason, the topological whole bead design was proposed, although it performs well, many defects existed due to the design based on traditional experience. Therefore, this paper studies the topology shape optimization algorithm, delves into the main criterion based on von Mises and the interlaminar shear stress, and provides guidance for the structurally optimal design of the 265/35R18 radial tire whole bead. The finite element simulation results show that the von Mises of the inner end of the chafer and the end of the carcass cord are reduced by 14.48% and 24.12%, respectively. The interlaminar shear stress decreased by 28.96% and 49.51%, respectively. The von Mises of chafer and carcass cord decreased by 13.17% to 40.36% and 7.71% to 20.51%, respectively. The optimization design is of great significance to further improve the safety performance of tires

Case report: Optical genome mapping revealed double rearrangements in a male undergoing preimplantation genetic testing

Chromosome rearrangement is one of the main causes of abortion. In individuals with double chromosomal rearrangements, the abortion rate and the risk of producing abnormal chromosomal embryos are increased. In our study, preimplantation genetic testing for structural rearrangement (PGT-SR) was performed for a couple because of recurrent abortion and the karyotype of the male was 45, XY der (14; 15)(q10; q10). The PGT-SR result of the embryo in this in vitro fertilization (IVF) cycle showed microduplication and microdeletion at the terminals of chromosomes 3 and 11, respectively. Therefore, we speculated whether the couple might have a cryptic reciprocal translocation which was not detected by karyotyping. Then, optical genome mapping (OGM) was performed for this couple, and cryptic balanced chromosomal rearrangements were detected in the male. The OGM data were consistent with our hypothesis according to previous PGT results. Subsequently, this result was verified by fluorescence in situ hybridization (FISH) in metaphase. In conclusion, the male’s karyotype was 45, XY, t(3; 11)(q28; p15.4), der(14; 15)(q10; q10). Compared with traditional karyotyping, chromosomal microarray, CNV-seq and FISH, OGM has significant advantages in detecting cryptic and balanced chromosomal rearrangements

Simulation of dieless clinching process considering the limit of blank holder

The low strength and large protrusion of the traditional dieless clinched joint hindered its application. To improve the mechanical properties of the dieless clinched joint, a novel dieless clinching process considering the limitation of the blank holder was proposed. The finite element model of the dieless clinching process was established by DEFORM-2D, the influences of the blank holder spring stiffness, the blank holder limit height, and the punch diameter on the mechanical interlock of the joint were analyzed, and the influence laws of blank holder spring stiffness and blank holder limit height on material flow and mechanical interlock were obtained. Then, the influence of these three die parameters and their interaction on the joint interlock were analyzed using the response surface method. The results show that the blank holder displacement plays a key role in the formation of mechanical interlock in the dieless clinching process. Reasonable limit height and spring stiffness of the blank holder can control the flow direction of materials, so as to improve the mechanical interlock and the strength of dieless clinched joints. It provides a new idea for improving the dieless clinching process

Experimental Investigation and Constitutive Modeling of the Uncured Rubber Compound Based on the DMA Strain Scanning Method

Existing research tends to focus on the performance of cured rubber. This is due to a lack of suitable testing methods for the mechanical properties of uncured rubber, in particular, tensile properties. Without crosslinking by sulfur, the tensile strength of uncured rubber compounds is too low to be accurately tested by general tensile testing machines. Firstly, a new tensile stress testing method for uncured rubber was established by using dynamic thermomechanical analysis (DMA) tensile strain scanning. The strain amplitude was increased under a set frequency and constant temperature. The corresponding dynamic force needed to maintain the amplitude was then measured to obtain the dynamic force-amplitude curve observed at this temperature and frequency. Secondly, the Burgers model is usually difficult to calculate and analyze in differential form, so it was reduced to its arithmetic form under creep conditions and material relaxation. Tensile deformation at a constant strain rate was proposed, so the Burgers model could be modified to a more concise form without any strain terms, making mathematical processing and simulating much more convenient. Thirdly, the rate of the modified Burgers model under constant strain was in good agreement with the test data, demonstrating that the elastic stiffness was 1–2 orders of magnitude less than the tensile viscosity. In the end, it was concluded that large data dispersion caused by the universal tensile test can be overcome by choosing this model, and it may become an effective way to study the tensile modeling of uncured rubber compound

Design and Analysis of Fused Deposition Modeling 3D Printer Nozzle for Color Mixing

Fused deposition modeling (FDM) has been one of the most widely used rapid prototyping (RP) technologies leading to the increase in market attention. Obviously it is desirable to print 3D objects; however, existing FDM printers are restricted to printing only monochrome objects because of the entry-level nozzle structure, and literature on the topic is also sparse. In this paper, the CAD model of the nozzle is established first by UG (Unigraphics NX) software to show the structure of fused deposition modeling 3D printer nozzle for color mixing. Second, the flow channel model of the nozzle is extracted and simplified. Then, the CAD and finite element model are established by UG and ICEM CFD software, respectively, to prepare for the simulation. The flow field is simulated by Fluent software. The nozzle’s suitable temperature at different extrusion speeds is obtained, and the reason for the blockage at the intersection of the heating block is revealed. Finally, test verification of the nozzle is performed, which can produce mixed-color artifacts stably

Revealing the microstructures and seepage characteristics in the uncured rubber-cord composites using micro-computed tomography and lattice Boltzmann approach

The internal microstructure distribution of cord-rubber-air during the processing of uncured rubber-cord composites (URCs) determines the finished product's performance. For the first time, we used computed tomography (CT) and the lattice Boltzmann method (LBM) to establish a geometrical representation model of the real microscopic pore-fracture structures of URCs and investigate the seepage law of fluid in porous URCs, where the reinforced rubber formula was originally designed to reduce CT artifacts of cord. The results showed that the average porosity and pore radius of the original cord (0.2711 and 15.53 μm, respectively) were considerably larger than those of the URCs (0.0509 and 4.46 μm, respectively); the pore number of the cord was the largest when the pore radius was 5–10 μm, accounting for 29.36% of the total number; however, the pore number accounted for 31.36% of the total number of the URCs when the pore radius was 2–3 μm. Moreover, the characteristics of the pore/throat surface area and pore volume/throat length exhibited perfect consistent patterns with those of the pore radius. Furthermore, the fluid flow velocity increased in both cord and URCs as the displacement differential pressure increased, but decreased dramatically as the fluid kinematic viscosity increased. The critical values of displacement differential pressure and kinematic viscosity were different in the cord and URCs samples, presenting 11.1209 Pa/1.3696 × 10−3 m2/s and 14.2984 Pa/2.8869 × 10−4 m2/s, respectively. This phenomenon should be attributed that when the uncured rubber was injected into the original cord sample, its porosity decreased, its pore radius decreased, the number of micro-scale pores increased, and flow resistance became larger, resulting in a higher critical value of displacement differential pressure and a lower critical value of kinematic viscosity

Preimplantation genetic testing in couples with balanced chromosome rearrangement: a four-year period real world retrospective cohort study

Abstract Background Couples with balanced chromosome rearrangement (BCR) are at high risk of recurrent miscarriages or birth defects due to chromosomally abnormal embryos. This study aimed to provide real-world evidence of the euploidy rate of blastocysts from couples with BCR using preimplantation genetic testing (PGT) and to guide pretesting genetic counselling. Methods A continuous four-year PGT data from couples with BCR were retrospectively analyzed. Biopsied trophectoderm cells were amplified using whole genome amplification, and next-generation sequencing was performed to detect the chromosomal numerical and segmental aberrations. Clinical data and molecular genetic testing results were analyzed and compared among the subgroups. Results A total of 1571 PGT cycles with 5942 blastocysts were performed chromosomal numerical and segmental aberrations detection during the four years. Of them, 1034 PGT cycles with 4129 blastocysts for BCR couples were included; 68.96% (713/1034) PGT cycles had transferable euploid embryos. The total euploidy rate of blastocysts in couples carrying the BCR was 35.29% (1457/4129). Couples with complex BCR had euploid blastocyst rates similar to those of couples with non-complex BCR (46.15% vs. 35.18%, P > 0.05). Chromosome inversion had the highest chance of obtaining a euploid blastocyst (57.27%), followed by Robertsonian translocation (RobT) (46.06%), and the lowest in reciprocal translocation (RecT) (30.11%) (P  0.05). RecT had the highest proportion of blastocysts with translocated chromosome-associated abnormalities (74.23%, 1527/2057), followed by RobT (54.60%, 273/500) and inversion (30.85%, 29/94) (P < 0.05). Conclusions In couples carrying BCR, the total euploidy rate of blastocysts was 35.29%, with the highest in inversion, followed by RobT and RecT. Even in couples carrying complex BCR, the probability of having a transferable blastocyst was 46.15%. Among the euploid blastocysts, the non-carrier ratios in RecT and RobT were 52.78% and 47.06%, respectively. RecT had the highest proportion of blastocysts with translocated chromosome-associated abnormalities

Capillary non-Newtonian seepage model of unvulcanized rubber expressed by the four-parameter rheological flow

Micro-bubbles and pores in a tire, generated by the seepage process of rubber into steel cord, seriously degrade the safety of the tire in use. However, unclear seepage behavior of unvulcanized rubber while flowing into the interstice of steel cord makes it difficult to eliminate defects. Here, we studied the seepage behavior of unvulcanized rubber in a single capillary. When the four-parameter rheological flow was compared to the common shear rheological model, it was best suited to represent the rheological behavior of unvulcanized rubber because of its lowest variance. On this basis, the single capillary seepage equation of unvulcanized rubber was developed to interpret the relationship between the flow rate, process length, pressure, and pore diameter in a single capillary tube. And it was validated by the finite element analysis method with the four-parameter rheological equation as the material parameter; the accuracy of the single capillary seepage equation reached 99.95%. It lays a foundation for further exploring the seepage model under complex conditions such as variable aperture and multiple channels

A long-read sequencing and SNP haplotype-based novel preimplantation genetic testing method for female ADPKD patient with de novo PKD1 mutation

Abstract The autosomal dominant form of polycystic kidney disease (ADPKD) is the most common hereditary disease that causes late-onset renal cyst development and end-stage renal disease. Preimplantation genetic testing for monogenic disease (PGT-M) has emerged as an effective strategy to prevent pathogenic mutation transmission rely on SNP linkage analysis between pedigree members. Yet, it remains challenging to establish reliable PGT-M methods for ADPKD cases or other monogenic diseases with de novo mutations or without a family history. Here we reported the application of long-read sequencing for direct haplotyping in a female patient with de novo PKD1 c.11,526 G > C mutation and successfully established the high-risk haplotype. Together with targeted short-read sequencing of SNPs for the couple and embryos, the carrier status for embryos was identified. A healthy baby was born without the PKD1 pathogenic mutation. Our PGT-M strategy based on long-read sequencing for direct haplotyping combined with targeted SNP haplotype can be widely applied to other monogenic disease carriers with de novo mutation