Mohanraj Selvakumar - Academia.edu (original) (raw)

Papers by Mohanraj Selvakumar

Research paper thumbnail of Reliability-Based Design Optimization of Pump Penetration Shell Accounting for Material and Geometric Non-Linearity

The roof slab of the nuclear reactor supports all the components and sub-systems. Roof slab needs... more The roof slab of the nuclear reactor supports all the components and sub-systems. Roof slab needs to resist the seismic loads in accordance with load-carrying criteria. The static stress analysis of the reactor roof slab reveals that high-stress concentration was present in the pump penetration shell (PPS) which supports the primary sodium pump. This paper presents the assessment of collapse load and optimization of pump penetration shell, through the reliability approach, accounting for material nonlinearity, geometrical nonlinearity and randomness in loading. In addition to that, the load-carrying capacity of PPS was determined considering two different materials, viz., IS2062 and A48P2. The design of experiments (DoE) was formulated considering the flange angle and flange thickness as parameters. An empirical model for load function was formulated from the results of the collapse load obtained for various combinations of design parameters. The above function was used to perform t...

Research paper thumbnail of Investigation of chatter stability in high speed milling on thin ribs

Journal of Physics: Conference Series, 2019

Chatter is a self-excited vibration that occurs during high speed machining of parts which is an ... more Chatter is a self-excited vibration that occurs during high speed machining of parts which is an undesirable phenomenon that affects work piece and also the tool. Chatter mainly depends upon the stiffness, the damping ratio of the material, the force applied and the clamped area. As the machined area continuously changes, the chatter stability of the work piece also changes continuously. The change in natural frequency of Aluminium 7010 T7651 thin rib during milling is calculated by using Modal analysis in ANSYS Workbench. The model is validated with published journal results and experimentally. Also, the scaled-down model of thin rib for same geometry is analysed for any change in natural frequency. The polynomial fit equation for finding instantaneous frequency of thin rib has been found which is applicable for same geometry irrespective of its scale. Using the equation, Stiffness is found and 2D Stability Lobe Diagram has been plotted and chatter free machining has been carried out experimentally in both stable and unstable regions to prove chatter zones. Also it was found that varying spindle speed is easier approach to avoid chatter during milling.

Research paper thumbnail of Optimization of Process Parameters of Epoxy Granite for Strength and Damping Characteristics Using TOPSIS Method

Journal of Testing and Evaluation

Research paper thumbnail of Genomic organization and chromosomal location of the human gene encoding the B-lymphocyte activation antigen B7

Immunogenetics, 1992

The human B lymphocyte activation antigen B7 provides regulatory signals for T lymphocytes as a c... more The human B lymphocyte activation antigen B7 provides regulatory signals for T lymphocytes as a consequence of binding to its ligands CD28 and CTLA-4. The cDNA for B7 has previously been isolated and predicted to encode a type I membrane protein. The predicted polypeptide has a secretory signal peptide followed by two contiguous Ig-like domains, a hydrophobic transmembrane region and a short cytoplasmic tail. Here we report the exon-intron genomic organization of human B7 and the chromosomal location. The gene has six exons that span approximately 32 kilobases of DNA. Exon 1 is not translated and the second exon contains the initiation ATG codon and encodes a predicted signal peptide. This gene structure is characteristic for several eukaryotic genes with tissue-specific expression. The third and fourth exons correspond to two Ig-like domains whereas the fifth and sixth exons encode respectively the trans-membrane portion and the cytoplasmic tail. This close relationship between exons and functional domains is a characteristic feature of genes of the Ig superfamily. Cell surface expression of the B7 gene product has previously been mapped to human chromosome 12 by antibody reactivity with the B7-specific monoclonal antibody BB-1. We here demonstrate that theB7 gene is located to theq21-qter region of chromosome 3 by DNA blot analysis of human × rodent somatic cell hybrids.

Research paper thumbnail of Kinematic Modeling and Simulation of a SCARA Robot by Using Solid Dynamics and Verification by MATLAB/Simulink

Simulation of robot systems which is getting very popular, especially with the lowering cost of c... more Simulation of robot systems which is getting very popular, especially with the lowering cost of computers, can be used for layout evaluation, feasibility studies, presentations with animation and off-line programming .

Research paper thumbnail of Reliability-Based Design Optimization of Pump Penetration Shell Accounting for Material and Geometric Non-Linearity

The roof slab of the nuclear reactor supports all the components and sub-systems. Roof slab needs... more The roof slab of the nuclear reactor supports all the components and sub-systems. Roof slab needs to resist the seismic loads in accordance with load-carrying criteria. The static stress analysis of the reactor roof slab reveals that high-stress concentration was present in the pump penetration shell (PPS) which supports the primary sodium pump. This paper presents the assessment of collapse load and optimization of pump penetration shell, through the reliability approach, accounting for material nonlinearity, geometrical nonlinearity and randomness in loading. In addition to that, the load-carrying capacity of PPS was determined considering two different materials, viz., IS2062 and A48P2. The design of experiments (DoE) was formulated considering the flange angle and flange thickness as parameters. An empirical model for load function was formulated from the results of the collapse load obtained for various combinations of design parameters. The above function was used to perform t...

Research paper thumbnail of Investigation of chatter stability in high speed milling on thin ribs

Journal of Physics: Conference Series, 2019

Chatter is a self-excited vibration that occurs during high speed machining of parts which is an ... more Chatter is a self-excited vibration that occurs during high speed machining of parts which is an undesirable phenomenon that affects work piece and also the tool. Chatter mainly depends upon the stiffness, the damping ratio of the material, the force applied and the clamped area. As the machined area continuously changes, the chatter stability of the work piece also changes continuously. The change in natural frequency of Aluminium 7010 T7651 thin rib during milling is calculated by using Modal analysis in ANSYS Workbench. The model is validated with published journal results and experimentally. Also, the scaled-down model of thin rib for same geometry is analysed for any change in natural frequency. The polynomial fit equation for finding instantaneous frequency of thin rib has been found which is applicable for same geometry irrespective of its scale. Using the equation, Stiffness is found and 2D Stability Lobe Diagram has been plotted and chatter free machining has been carried out experimentally in both stable and unstable regions to prove chatter zones. Also it was found that varying spindle speed is easier approach to avoid chatter during milling.

Research paper thumbnail of Optimization of Process Parameters of Epoxy Granite for Strength and Damping Characteristics Using TOPSIS Method

Journal of Testing and Evaluation

Research paper thumbnail of Genomic organization and chromosomal location of the human gene encoding the B-lymphocyte activation antigen B7

Immunogenetics, 1992

The human B lymphocyte activation antigen B7 provides regulatory signals for T lymphocytes as a c... more The human B lymphocyte activation antigen B7 provides regulatory signals for T lymphocytes as a consequence of binding to its ligands CD28 and CTLA-4. The cDNA for B7 has previously been isolated and predicted to encode a type I membrane protein. The predicted polypeptide has a secretory signal peptide followed by two contiguous Ig-like domains, a hydrophobic transmembrane region and a short cytoplasmic tail. Here we report the exon-intron genomic organization of human B7 and the chromosomal location. The gene has six exons that span approximately 32 kilobases of DNA. Exon 1 is not translated and the second exon contains the initiation ATG codon and encodes a predicted signal peptide. This gene structure is characteristic for several eukaryotic genes with tissue-specific expression. The third and fourth exons correspond to two Ig-like domains whereas the fifth and sixth exons encode respectively the trans-membrane portion and the cytoplasmic tail. This close relationship between exons and functional domains is a characteristic feature of genes of the Ig superfamily. Cell surface expression of the B7 gene product has previously been mapped to human chromosome 12 by antibody reactivity with the B7-specific monoclonal antibody BB-1. We here demonstrate that theB7 gene is located to theq21-qter region of chromosome 3 by DNA blot analysis of human × rodent somatic cell hybrids.

Research paper thumbnail of Kinematic Modeling and Simulation of a SCARA Robot by Using Solid Dynamics and Verification by MATLAB/Simulink

Simulation of robot systems which is getting very popular, especially with the lowering cost of c... more Simulation of robot systems which is getting very popular, especially with the lowering cost of computers, can be used for layout evaluation, feasibility studies, presentations with animation and off-line programming .