TY  - JOUR
A1  - Altherr, Lena
A1  - Ederer, Thorsten
A1  - Pöttgen, Philipp
A1  - Lorenz, Ulf
A1  - Pelz, Peter F.
ED  - Pelz, Peter F.
ED  - Groche, Peter
T1  - Multicriterial optimization of technical systems considering multiple load and availability scenarios
JF  - Applied Mechanics and Materials
N2  - Cheap does not imply cost-effective -- this is rule number one of zeitgeisty system design. The initial investment accounts only for a small portion of the lifecycle costs of a technical system. In fluid systems, about ninety percent of the total costs are caused by other factors like power consumption and maintenance. With modern optimization methods, it is already possible to plan an optimal technical system considering multiple objectives. In this paper, we focus on an often neglected contribution to the lifecycle costs: downtime costs due to spontaneous failures. Consequently, availability becomes an issue.
KW  - sustainability
KW  - availability
KW  - energy efficiency
KW  - mixed-integer linear programming
KW  - system synthesis
Y1  - 2015
SN  - 1660-9336
U6  - http://dx.doi.org/10.4028/www.scientific.net/AMM.807.247
VL  - 807
SP  - 247
EP  - 256
ER  - 
TY  - CHAP
A1  - Lorenz, Imke-Sophie
A1  - Altherr, Lena
A1  - Pelz, Peter F.
T1  - Resilience enhancement of critical infrastructure – graph-theoretical resilience analysis of the water distribution system in the German city of Darmstadt
T2  - 14th WCEAM Proceedings
N2  - Water suppliers are faced with the great challenge of achieving high-quality and, at the same time, low-cost water supply. Since climatic and demographic influences will pose further challenges in the future, the resilience enhancement of water distribution systems (WDS), i.e. the enhancement of their capability to withstand and recover from disturbances, has been in particular focus recently. To assess the resilience of WDS, graph-theoretical metrics have been proposed. In this study, a promising approach is first physically derived analytically and then applied to assess the resilience of the WDS for a district in a major German City. The topology based resilience index computed for every consumer node takes into consideration the resistance of the best supply path as well as alternative supply paths. This resistance of a supply path is derived to be the dimensionless pressure loss in the pipes making up the path. The conducted analysis of a present WDS provides insight into the process of actively influencing the resilience of WDS locally and globally by adding pipes. The study shows that especially pipes added close to the reservoirs and main branching points in the WDS result in a high resilience enhancement of the overall WDS.
KW  - Resilient infrastructure
KW  - Resilience assessment
KW  - Resilience metric graph theory
KW  - Water distribution system
KW  - Case study
Y1  - 2020
SN  - 978-3-030-64228-0
SN  - 978-3-030-64227-3
U6  - http://dx.doi.org/10.1007/978-3-030-64228-0_13
N1  - 14th WCEAM Proceedings. World Congress on Engineering Asset Management, 28-31 July 2019, Singapore

Part of the Lecture Notes in Mechanical Engineering book series (LNME)
SP  - 137
EP  - 149
PB  - Springer
CY  - Cham
ER  -